diff --git a/target/bin/addalias b/target/bin/addalias
index ad171e46..b5d136ef 100755
--- a/target/bin/addalias
+++ b/target/bin/addalias
@@ -3,26 +3,37 @@
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE='/tmp/docker-mailserver/postfix-virtual.cf'
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
+
+  local MAIL_ALIAS="${1}"
+  local RECIPIENT="${2}"
+
+  _manage_virtual_aliases_update "${MAIL_ALIAS}" "${RECIPIENT}" \
+    || _exit_with_error "'${MAIL_ALIAS}' is already an alias for recipient: '${RECIPIENT}'"
+}
 
 function __usage
 {
-  printf '%s' "${PURPLE}ADDALIAS${RED}(${YELLOW}8${RED})
+  printf '%s' "${PURPLE}addalias${RED}(${YELLOW}8${RED})
 
-${ORANGE}NAME${RESET}
-    addalias - add an email alias for an existing user
-
-${ORANGE}SYNOPSIS${RESET}
-    ./setup.sh alias add <EMAIL ADDRESS> <RECIPIENT>
+${ORANGE}USAGE${RESET}
+    ./setup.sh alias add <MAIL ALIAS> <RECIPIENT>
 
 ${ORANGE}OPTIONS${RESET}
     ${BLUE}Generic Program Information${RESET}
         help       Print the usage information.
 
+${ORANGE}DESCRIPTION${RESET}
+    Add an alias for a recipient (a mail account).
+
+    Alias and recipient domains can be different.
+    The recipient domain can be external (eg: @gmail.com).
+
 ${ORANGE}EXAMPLES${RESET}
-    ${LWHITE}./setup.sh alias add alias-for-me@domain.tld admin@domain.tld${RESET}
-        Add the alias alias-for-me@doamin.tld for the existing user
-        admin@domain.tld.
+    ${LWHITE}./setup.sh alias add alias@example.com recipient@example.com${RESET}
+        Add the alias 'alias@example.com' for the mail account 'recipient@example.com'.
 
 ${ORANGE}EXIT STATUS${RESET}
     Exit status is 0 if command was successful. If wrong arguments are provided
@@ -31,21 +42,4 @@ ${ORANGE}EXIT STATUS${RESET}
 "
 }
 
-[[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
-
-EMAIL="${1}"
-RECIPIENT="${2}"
-
-[[ -z ${EMAIL} ]] && { __usage ; _exit_with_error 'No alias specified' ; }
-[[ -z ${RECIPIENT} ]] && { __usage ; _exit_with_error 'No recipient specified' ; }
-
-grep \
-  -qi "^$(_escape "${EMAIL}")[a-zA-Z@.\ ]*$(_escape "${RECIPIENT}")" \
-  "${DATABASE}" 2>/dev/null && _exit_with_error "Alias \"${EMAIL} ${RECIPIENT}\" already exists"
-
-if grep -qi "^$(_escape "${EMAIL}")" "${DATABASE}" 2>/dev/null
-then
-  sed -i "/${EMAIL}/s/$/,${RECIPIENT}/" "${DATABASE}"
-else
-  echo "${EMAIL} ${RECIPIENT}" >> "${DATABASE}"
-fi
+_main "${@}"
diff --git a/target/bin/adddovecotmasteruser b/target/bin/adddovecotmasteruser
index 2fd31572..0f7d47ce 100755
--- a/target/bin/adddovecotmasteruser
+++ b/target/bin/adddovecotmasteruser
@@ -1,30 +1,41 @@
 #! /bin/bash
 
-# shellcheck disable=SC2094
-
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE=/tmp/docker-mailserver/dovecot-masters.cf
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
+
+  local MAIL_ACCOUNT="${1}"
+  shift
+  local PASSWD="${*}"
+
+  _manage_accounts_dovecotmaster_create "${MAIL_ACCOUNT}" "${PASSWD}"
+}
 
 function __usage
 {
-  printf '%s' "${PURPLE}ADDDOVECOTMASTERUSER${RED}(${YELLOW}8${RED})
+  printf '%s' "${PURPLE}adddovecotmasteruser${RED}(${YELLOW}8${RED})
 
-${ORANGE}NAME${RESET}
-    addmasteruser - add a dovecot master user (for POP3/IMAP administration)
-
-${ORANGE}SYNOPSIS${RESET}
-    ./setup.sh dovecot-master add <USERNAME> [<PASSWORD>]
+${ORANGE}USAGE${RESET}
+    ./setup.sh dovecot-master add <MASTER ACCOUNT> [<PASSWORD>]
 
 ${ORANGE}OPTIONS${RESET}
     ${BLUE}Generic Program Information${RESET}
         help       Print the usage information.
 
+${ORANGE}DESCRIPTION${RESET}
+    Add a new dovecot-master account (for POP3/IMAP administration).
+
+    To avoid a password being logged in the command history of your shell,
+    you may omit it, you'll be prompted to input the password instead.
+
 ${ORANGE}EXAMPLES${RESET}
-    ${LWHITE}./setup.sh dovecot-master add test-user${RESET}
-        Add the dovecot master account 'test-user'. You will be prompted
-        to input a password afterwards since no password was supplied.
+    ${LWHITE}./setup.sh dovecot-master add example-account${RESET}
+        Create the dovecot-master account 'example-account'.
+
+        You will be prompted to input a password afterwards since no password was supplied.
 
 ${ORANGE}EXIT STATUS${RESET}
     Exit status is 0 if command was successful. If wrong arguments are provided
@@ -33,27 +44,4 @@ ${ORANGE}EXIT STATUS${RESET}
 "
 }
 
-[[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
-
-USERNAME="${1}"
-shift
-PASSWD="${*}"
-
-[[ -z ${USERNAME} ]] && { __usage ; _exit_with_error 'No username specified' ; }
-
-touch "${DATABASE}"
-_create_lock # Protect config file with lock to avoid race conditions
-if grep -qi "^$(_escape "${USERNAME}")|" "${DATABASE}"
-then
-  _exit_with_error "User '${USERNAME}' already exists"
-fi
-
-if [[ -z ${PASSWD} ]]
-then
-  read -r -s -p "Enter Password: " PASSWD
-  echo
-  [[ -z ${PASSWD} ]] && _exit_with_error "Password must not be empty"
-fi
-
-HASH="$(doveadm pw -s SHA512-CRYPT -u "${USERNAME}" -p "${PASSWD}")"
-echo "${USERNAME}|${HASH}" >> "${DATABASE}"
+_main "${@}"
diff --git a/target/bin/addmailuser b/target/bin/addmailuser
index 0be3b8a4..3827c68f 100755
--- a/target/bin/addmailuser
+++ b/target/bin/addmailuser
@@ -1,30 +1,45 @@
 #! /bin/bash
 
-# shellcheck disable=SC2094
-
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE='/tmp/docker-mailserver/postfix-accounts.cf'
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
+
+  local MAIL_ACCOUNT="${1}"
+  shift
+  local PASSWD="${*}"
+
+  _manage_accounts_create "${MAIL_ACCOUNT}" "${PASSWD}"
+
+  # Change Detection will be triggered from `postfix-accounts.cf` update,
+  # block until event processed (actual account creation handled there):
+  _wait_until_account_maildir_exists "${MAIL_ACCOUNT}"
+}
 
 function __usage
 {
-  printf '%s' "${PURPLE}ADDMAILUSER${RED}(${YELLOW}8${RED})
+  printf '%s' "${PURPLE}addmailuser${RED}(${YELLOW}8${RED})
 
-${ORANGE}NAME${RESET}
-    addmailuser - add an email address (i.e. a user)
-
-${ORANGE}SYNOPSIS${RESET}
-    ./setup.sh email add <EMAIL ADDRESS> [<PASSWORD>]
+${ORANGE}USAGE${RESET}
+    ./setup.sh email add <MAIL ACCOUNT> [<PASSWORD>]
 
 ${ORANGE}OPTIONS${RESET}
     ${BLUE}Generic Program Information${RESET}
         help       Print the usage information.
 
+${ORANGE}DESCRIPTION${RESET}
+    Add a new mail account (email address).
+
+    To avoid a password being logged in the command history of your shell,
+    you may omit it, you'll be prompted to input the password instead.
+
 ${ORANGE}EXAMPLES${RESET}
-    ${LWHITE}./setup.sh email add test@domain.tld${RESET}
-        Add the email account test@domain.tld. You will be prompted
-        to input a password afterwards since no password was supplied.
+    ${LWHITE}./setup.sh email add user@example.com${RESET}
+        Create the email account 'user@example.com'.
+
+        You will be prompted to input a password afterwards since no password was supplied.
 
 ${ORANGE}EXIT STATUS${RESET}
     Exit status is 0 if command was successful. If wrong arguments are provided
@@ -33,42 +48,37 @@ ${ORANGE}EXIT STATUS${RESET}
 "
 }
 
-[[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
-
-FULL_EMAIL="${1}"
-shift
-PASSWD="${*}"
-
-[[ -z ${FULL_EMAIL} ]] && { __usage ; _exit_with_error 'No username specified' ; }
-[[ ${FULL_EMAIL} =~ .*\@.* ]] || { __usage ; _exit_with_error 'Username must include the domain' ; }
-
-touch "${DATABASE}"
-_create_lock # Protect config file with lock to avoid race conditions
-if grep -qi "^$(_escape "${FULL_EMAIL}")|" "${DATABASE}"
-then
-  _exit_with_error "User '${FULL_EMAIL}' already exists"
-fi
-
-if [[ -z ${PASSWD} ]]
-then
-  read -r -s -p "Enter Password: " PASSWD
-  echo
-  [[ -z ${PASSWD} ]] && _exit_with_error "Password must not be empty"
-fi
-
-HASH=$(doveadm pw -s SHA512-CRYPT -u "${FULL_EMAIL}" -p "${PASSWD}")
-echo "${FULL_EMAIL}|${HASH}" >> "${DATABASE}"
-
-USER="${FULL_EMAIL%@*}"
-DOMAIN="${FULL_EMAIL#*@}"
-
+# TODO: Remove this method or at least it's usage in `addmailuser`. If tests are failing, correct the tests.
+#
+# This method was added to delay command completion until a change detection event had processed the newly added user,
+# confirmed once maildir was created. It was a workaround to accomodate the test suite apparently, but otherwise
+# prevents batch adding users (each one would have to go through their own change detection event).
+#
+# Originally introduced in PR 1980 (afterwards two futher PRs deleted, and then reverted that deletion):
+# https://github.com/docker-mailserver/docker-mailserver/pull/1980
+# Not much details/discussion in the PR, these are the specific commits:
+# - Initial commit: https://github.com/docker-mailserver/docker-mailserver/pull/1980/commits/2ed402a12cedd412abcf577e8079137ea05204fe#diff-92d2047e4a9a7965f6ef2f029dd781e09265b0ce171b5322a76e35b66ab4cbf4R67
+# - Follow-up commit: https://github.com/docker-mailserver/docker-mailserver/pull/1980/commits/27542867b20c617b63bbec6fdcba421b65a44fbb#diff-92d2047e4a9a7965f6ef2f029dd781e09265b0ce171b5322a76e35b66ab4cbf4R67
+#
+# Original reasoning for this method (sounds like a network storage I/O issue):
 # Tests fail if the creation of /var/mail/${DOMAIN}/${USER} doesn't happen fast enough after addmailuser executes (check-for-changes.sh race-condition)
 # Prevent infinite loop in tests like "checking accounts: user3 should have been added to /tmp/docker-mailserver/postfix-accounts.cf even when that file does not exist"
-if [[ -e ${CHKSUM_FILE} ]]
-then
-  while [[ ! -d "/var/mail/${DOMAIN}/${USER}" ]]
-  do
-    _log 'info' "Waiting for dovecot to create '/var/mail/${DOMAIN}/${USER}/'"
-    sleep 1
-  done
-fi
+function _wait_until_account_maildir_exists
+{
+  local MAIL_ACCOUNT=${1}
+
+  if [[ -f ${CHKSUM_FILE} ]]
+  then
+    local USER="${MAIL_ACCOUNT%@*}"
+    local DOMAIN="${MAIL_ACCOUNT#*@}"
+
+    local MAIL_ACCOUNT_STORAGE_DIR="/var/mail/${DOMAIN}/${USER}"
+    while [[ ! -d ${MAIL_ACCOUNT_STORAGE_DIR} ]]
+    do
+      _log 'info' "Waiting for dovecot to create '${MAIL_ACCOUNT_STORAGE_DIR}'"
+      sleep 1
+    done
+  fi
+}
+
+_main "${@}"
diff --git a/target/bin/addrelayhost b/target/bin/addrelayhost
index 3cb15a88..1bd606f5 100755
--- a/target/bin/addrelayhost
+++ b/target/bin/addrelayhost
@@ -3,22 +3,43 @@
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE='/tmp/docker-mailserver/postfix-relaymap.cf'
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
+
+  local DOMAIN="${1}"
+  local HOST="${2}"
+  local PORT="${3}"
+
+  _validate_parameters
+  _add_relayhost
+}
 
 function __usage
 {
-  printf '%s' "${PURPLE}ADDRELAYHOST${RED}(${YELLOW}8${RED})
+  printf '%s' "${PURPLE}addrelayhost${RED}(${YELLOW}8${RED})
 
-${ORANGE}NAME${RESET}
-    addrelayhost - add an relay host
-
-${ORANGE}SYNOPSIS${RESET}
-    ./setup.sh relay add-domain <DOMAIN> <HOST> [<PORT>]
+${ORANGE}USAGE${RESET}
+    ./setup.sh relay add-domain <SENDER DOMAIN> <RELAY HOST> [<RELAY PORT>]
 
 ${ORANGE}OPTIONS${RESET}
     ${BLUE}Generic Program Information${RESET}
         help       Print the usage information.
 
+${ORANGE}DESCRIPTION${RESET}
+    Add a relay-host where mail sent from mail accounts of the provided
+    domain will be relayed through to their destination.
+
+    If a port is not provided it will default to 25.
+
+    If the relay-host requires authentication, use the 'setup relay add-auth'
+    command after adding the relay-host.
+
+${ORANGE}EXAMPLES${RESET}
+    ${LWHITE}./setup.sh relay add-domain example.com relay.service.test 587${RESET}
+        Any mail submitted from your '@example.com' accounts will be sent via
+        relay using the relay-host service at 'relay.service.test:587'.
+
 ${ORANGE}EXIT STATUS${RESET}
     Exit status is 0 if command was successful. If wrong arguments are provided
     or arguments contain errors, the script will exit early with exit status 1.
@@ -26,21 +47,22 @@ ${ORANGE}EXIT STATUS${RESET}
 "
 }
 
-[[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
+function _validate_parameters
+{
+  [[ -z ${DOMAIN} ]] && { __usage ; _exit_with_error 'No domain specified'     ; }
+  [[ -z ${HOST}   ]] && { __usage ; _exit_with_error 'No relay host specified' ; }
+  [[ -z ${PORT}   ]] && PORT=25
+}
 
-DOMAIN="${1}"
-HOST="${2}"
-PORT="${3}"
+# Config is for sender dependent relay-host mapping,
+# current support restricts senders to domain scope (port is also enforced).
+function _add_relayhost
+{
+  local SENDER="@${DOMAIN}"
+  local RELAY_HOST_ENTRY="[${HOST}]:${PORT}"
+  local DATABASE_RELAY='/tmp/docker-mailserver/postfix-relaymap.cf'
 
-[[ -z ${DOMAIN} ]] && { __usage ; _exit_with_error 'No domain specified' ; }
-[[ -z ${HOST} ]] && { __usage ; _exit_with_error 'No relay host specified' ; }
-[[ -z ${PORT} ]] && PORT=25
+  _db_entry_add_or_replace "${DATABASE_RELAY}" "${SENDER}" "${RELAY_HOST_ENTRY}"
+}
 
-if grep -qi "^@${DOMAIN}" "${DATABASE}" 2>/dev/null
-then
-  sed -i \
-    "s|^@${DOMAIN}.*|@${DOMAIN}\t\t[${HOST}]:${PORT}|" \
-    "${DATABASE}"
-else
-  echo -e "@${DOMAIN}\t\t[${HOST}]:${PORT}" >>"${DATABASE}"
-fi
+_main "${@}"
diff --git a/target/bin/addsaslpassword b/target/bin/addsaslpassword
index 8428213d..d625d9d8 100755
--- a/target/bin/addsaslpassword
+++ b/target/bin/addsaslpassword
@@ -3,31 +3,68 @@
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE='/tmp/docker-mailserver/postfix-sasl-password.cf'
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
 
-function __usage { echo "Usage: addsaslpassword <domain> <username> <password>" ; }
+  local DOMAIN="${1}"
+  local RELAY_ACCOUNT="${2}"
+  shift 2
+  local PASSWD="${*}"
 
-[[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
+  _validate_parameters
+  _add_relayhost_credentials
+}
 
-DOMAIN="${1}"
-USER="${2}"
-PASSWD="${3}"
+function __usage
+{
+  printf '%s' "${PURPLE}addsaslpassword${RED}(${YELLOW}8${RED})
 
-[[ -z ${DOMAIN} ]] && { __usage ; _exit_with_error 'No domain specified' ; }
-[[ -z ${USER} ]] && { __usage ; _exit_with_error 'No username specified' ; }
+${ORANGE}USAGE${RESET}
+    ./setup.sh relay add-auth <SENDER DOMAIN> <RELAY ACCOUNT> [<RELAY PASSWORD>]
 
-if [[ -z ${PASSWD} ]]
-then
-  read -r -s -p "Enter Password: " PASSWD
-  echo
-  [[ -z ${PASSWD} ]] && _exit_with_error 'Password must not be empty'
-fi
+${ORANGE}OPTIONS${RESET}
+    ${BLUE}Generic Program Information${RESET}
+        help       Print the usage information.
 
-if grep -qi "^@${DOMAIN}" "${DATABASE}" 2>/dev/null
-then
-  sed -i \
-    "s|^@${DOMAIN}.*|@${DOMAIN}\t\t${USER}:${PASSWD}|" \
-    "${DATABASE}"
-else
-  echo -e "@${DOMAIN}\t\t${USER}:${PASSWD}" >>"${DATABASE}"
-fi
+${ORANGE}DESCRIPTION${RESET}
+    Add credentials to authenticate to a relay-host service.
+
+    To avoid a password being logged in the command history of your shell,
+    you may omit it, you'll be prompted to input the password instead.
+
+${ORANGE}EXAMPLES${RESET}
+    ${LWHITE}./setup.sh relay add-auth example.com relay-account${RESET}
+        Any mail submitted for your '@example.com' accounts that is sent
+        through a relay-host service will authenticate with the credentials:
+        'relay-account' + the password you entered at the prompt.
+
+${ORANGE}EXIT STATUS${RESET}
+    Exit status is 0 if command was successful. If wrong arguments are provided
+    or arguments contain errors, the script will exit early with exit status 1.
+
+"
+}
+
+function _validate_parameters
+{
+  [[ -z ${DOMAIN}        ]] && { __usage ; _exit_with_error 'No domain specified'        ; }
+  [[ -z ${RELAY_ACCOUNT} ]] && { __usage ; _exit_with_error 'No relay account specified' ; }
+  _password_request_if_missing
+}
+
+# Config is for sender dependent relay-host auth,
+# current support restricts senders to their domain scope.
+#
+# NOTE: This command does not support providing a relay-host
+# as the lookup key, it only supports a lookup via sender domain.
+function _add_relayhost_credentials
+{
+  local SENDER="@${DOMAIN}"
+  local RELAY_HOST_ENTRY_AUTH="${RELAY_ACCOUNT}:${PASSWD}"
+  local DATABASE_PASSWD='/tmp/docker-mailserver/postfix-sasl-password.cf'
+
+  _db_entry_add_or_replace "${DATABASE_PASSWD}" "${SENDER}" "${RELAY_HOST_ENTRY_AUTH}"
+}
+
+_main "${@}"
diff --git a/target/bin/delalias b/target/bin/delalias
index a07af1d2..1389b9a4 100755
--- a/target/bin/delalias
+++ b/target/bin/delalias
@@ -3,21 +3,40 @@
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE='/tmp/docker-mailserver/postfix-virtual.cf'
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
 
-EMAIL="${1}"
-RECIPIENT="${2}"
+  local MAIL_ALIAS="${1}"
+  local RECIPIENT="${2}"
 
-function __usage { echo "Usage: delalias <alias@domain> <recipient@other>" ; }
+  _manage_virtual_aliases_delete "${MAIL_ALIAS}" "${RECIPIENT}"
+}
 
-[[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
+function __usage
+{
+  printf '%s' "${PURPLE}delalias${RED}(${YELLOW}8${RED})
 
-[[ -z ${EMAIL} ]] && { __usage ; _exit_with_error 'No alias specified' ; }
-[[ -z ${RECIPIENT} ]] && { __usage ; _exit_with_error 'No recipient specified' ; }
-[[ -s ${DATABASE} ]] || exit 0
+${ORANGE}USAGE${RESET}
+    ./setup.sh alias del <MAIL ALIAS> <RECIPIENT>
 
-sed -i \
-  -e "/^${EMAIL} *${RECIPIENT}$/d" \
-  -e "/^${EMAIL}/s/,${RECIPIENT}//g" \
-  -e "/^${EMAIL}/s/${RECIPIENT},//g" \
-  "${DATABASE}"
+${ORANGE}OPTIONS${RESET}
+    ${BLUE}Generic Program Information${RESET}
+        help       Print the usage information.
+
+${ORANGE}DESCRIPTION${RESET}
+    Remove a mail account (the recipient) from an existing alias.
+    If the alias has no more recipients, the alias will also be removed.
+
+${ORANGE}EXAMPLES${RESET}
+    ${LWHITE}./setup.sh alias del alias@example.com recipient@example.com${RESET}
+        Remove the account 'recipient@example.com' from the alias 'alias@example.com'.
+
+${ORANGE}EXIT STATUS${RESET}
+    Exit status is 0 if command was successful. If wrong arguments are provided
+    or arguments contain errors, the script will exit early with exit status 1.
+
+"
+}
+
+_main "${@}"
diff --git a/target/bin/deldovecotmasteruser b/target/bin/deldovecotmasteruser
index b5f20cfd..9e12f716 100755
--- a/target/bin/deldovecotmasteruser
+++ b/target/bin/deldovecotmasteruser
@@ -1,75 +1,49 @@
 #! /bin/bash
 
-# shellcheck disable=SC2094
-# ? This is done to ignore the message "Make sure not to read and write
-# ? the same file in the same pipeline", which is a result of ${DATABASE}
-# ? being used below. (This disables the message file-wide.)
-
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE=/tmp/docker-mailserver/dovecot-masters.cf
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
+
+  # Validate Parameters:
+  [[ -z ${*} ]] && { __usage ; _exit_with_error 'No account specified' ; }
+
+  # Actual command to perform:
+  for MAIL_ACCOUNT in "${@}"
+  do
+    _manage_accounts_dovecotmaster_delete "${MAIL_ACCOUNT}" \
+      || _exit_with_error "'${MAIL_ACCOUNT}' could not be deleted"
+  done
+}
 
 function __usage
 {
-  printf '%s' "${PURPLE}DELDOVECOTMASTERUSER${RED}(${YELLOW}8${RED})
+  printf '%s' "${PURPLE}deldovecotmasteruser${RED}(${YELLOW}8${RED})
 
-${ORANGE}NAME${RESET}
-    deldovecotmasteruser - delete a dovecot master user
-
-${ORANGE}SYNOPSIS${RESET}
-    ./setup.sh dovecot-master del [ OPTIONS ] { <MAIL ADDRESS> [<MAIL ADDRESS>${RED}...${RESET}] ${RED}|${RESET} help }
-
-${ORANGE}DESCRIPTION${RESET}
-    Delete a dovecot master user.
+${ORANGE}USAGE${RESET}
+    ./setup.sh dovecot-master del <MASTER ACCOUNT> [<EXTRA MASTER ACCOUNTS> ${RED}...${RESET} ]
 
 ${ORANGE}OPTIONS${RESET}
-    -h
-        Show this help dialogue.
+    ${BLUE}Generic Program Information${RESET}
+        help       Print the usage information.
+
+${ORANGE}DESCRIPTION${RESET}
+    Delete a dovecot-master account.
 
 ${ORANGE}EXAMPLES${RESET}
-    ${LWHITE}./setup.sh dovecot-master del administrator${RESET}
-        Delete the dovecot master user called 'administrator'.
+    ${LWHITE}./setup.sh dovecot-master del admin${RESET}
+        Delete the dovecot-master account 'admin'.
 
-    ${LWHITE}./setup.sh dovecot-master del administrator admin${RESET}
-        Delete dovecot master users 'administrator' and 'admin'.
+    ${LWHITE}./setup.sh dovecot-master del admin extra-admin${RESET}
+        Delete the two dovecot-master accounts requested.
 
 ${ORANGE}EXIT STATUS${RESET}
-    Exit status is 0 if command was successful, and 1 if there was an error.
+    Exit status is 0 if command was successful. If wrong arguments are provided
+    or arguments contain errors, the script will exit early with exit status 1.
+
 "
 }
 
-if [[ ${1} == 'help' ]]
-then
-  __usage
-  exit 0
-fi
-
-shift $((OPTIND-1))
-
-[[ -z ${*} ]] && { __usage ; _exit_with_error 'No user specified' ; }
-[[ -s ${DATABASE} ]] || exit 0
-
-_create_lock # Protect config file with lock to avoid race conditions
-
-for USER in "${@}"
-do
-  ERROR=false
-
-  # ${USER} must not contain /s and other syntactic characters
-  UNESCAPED_USER="${USER}"
-  USER=$(_escape "${USER}")
-
-  if [[ -f ${DATABASE} ]]
-  then
-    if ! sedfile --strict -i "/^${USER}|/d" "${DATABASE}"
-    then
-      _log 'error' "'${UNESCAPED_USER}' couldn't be deleted in '${DATABASE}'"
-      ERROR=true
-    fi
-  fi
-
-  ${ERROR} && _exit_with_error 'See the messages above.'
-done
-
-exit 0
+_main "${@}"
diff --git a/target/bin/delmailuser b/target/bin/delmailuser
index bf929d7a..7424e113 100755
--- a/target/bin/delmailuser
+++ b/target/bin/delmailuser
@@ -1,161 +1,130 @@
 #! /bin/bash
 
-# shellcheck disable=SC2094
-# ? This is done to ignore the message "Make sure not to read and write
-# ? the same file in the same pipeline", which is a result of ${DATABASE}
-# ? being used below. (This disables the message file-wide.)
-
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE='/tmp/docker-mailserver/postfix-accounts.cf'
-ALIAS_DATABASE='/tmp/docker-mailserver/postfix-virtual.cf'
-QUOTA_DATABASE='/tmp/docker-mailserver/dovecot-quotas.cf'
-MAILDEL='false'
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
+  # Tests expect early exit without error if no DB exists:
+  [[ -s ${DATABASE_ACCOUNTS} ]] || return 0
+
+  # Validate Parameters:
+  [[ -z ${*} ]] && { __usage ; _exit_with_error 'No account specified' ; }
+  _maildel_request_if_missing
+
+  # TODO: May want to lock all database files prior to loop? (DATABASE_ACCOUNTS DATABASE_QUOTA DATABASE_VIRTUAL)
+  # NOTE: Present lock method locks the original sourcing script itself.
+  _create_lock
+
+  # Actual command to perform:
+  for MAIL_ACCOUNT in "${@}"
+  do
+    _account_should_already_exist
+
+    [[ ${MAILDEL} -eq 1 ]] && _remove_maildir "${MAIL_ACCOUNT}"
+
+    _manage_virtual_aliases_delete '_' "${MAIL_ACCOUNT}" \
+      || _exit_with_error "Aliases for '${MAIL_ACCOUNT}' could not be deleted"
+
+    _manage_dovecot_quota_delete "${MAIL_ACCOUNT}" \
+      || _exit_with_error "Quota for '${MAIL_ACCOUNT}' could not be deleted"
+
+    # Performed last, avoids breaking command if a prior failure occurred
+    _manage_accounts_delete "${MAIL_ACCOUNT}" \
+      || _exit_with_error "'${MAIL_ACCOUNT}' could not be deleted"
+
+    _log 'info' "'${MAIL_ACCOUNT}' and associated data deleted"
+  done
+}
 
 function __usage
 {
-  printf '%s' "${PURPLE}DELMAILUSER${RED}(${YELLOW}8${RED})
+  printf '%s' "${PURPLE}delmailuser${RED}(${YELLOW}8${RED})
 
-${ORANGE}NAME${RESET}
-    delmailuser - delete a user and related data
-
-${ORANGE}SYNOPSIS${RESET}
-    ./setup.sh email del [ OPTIONS ] { <MAIL ADDRESS> [<MAIL ADDRESS>${RED}...${RESET}] ${RED}|${RESET} help }
-
-${ORANGE}DESCRIPTION${RESET}
-    Delete a mail user, aliases, quotas and mail data.
+${ORANGE}USAGE${RESET}
+    ./setup.sh email del [ OPTIONS ] <MAIL ACCOUNT> [<EXTRA MAIL ACCOUNTS> ${RED}...${RESET} ]
 
 ${ORANGE}OPTIONS${RESET}
     -y
-        Indicate that ${LWHITE}all mail data${RESET} is to be deleted without another prompt.
+        Skip prompt by approving to ${LWHITE}delete all mail storage${RESET} for the account(s).
 
-    -h
-        Show this help dialogue.
+    ${BLUE}Generic Program Information${RESET}
+        help       Print the usage information.
+
+${ORANGE}DESCRIPTION${RESET}
+    Delete a mail account, including associated data (aliases, quotas) and
+    optionally the mailbox storage for that account.
 
 ${ORANGE}EXAMPLES${RESET}
-    ${LWHITE}./setup.sh email del woohoo@some-domain.org${RESET}
-        Delete the mail user, quotas and aliases, but ask
-        again whether mailbox data should be deleted.
+    ${LWHITE}./setup.sh email del user@example.com${RESET}
+        Delete the mail account 'user@example.com' and associated data,
+        but ask if mailbox data should also be deleted.
 
-    ${LWHITE}./setup.sh email del -y test@domain.com test@domain.com${RESET}
-        Delete all mail data for the users 'test' and do not
-        prompt to ask if all mail data should be deleted.
+    ${LWHITE}./setup.sh email del -y user@example.com extra-user@example.com${RESET}
+        Delete the two mail accounts requested, their associated data and
+        delete the mailbox data for both accounts without asking.
 
 ${ORANGE}EXIT STATUS${RESET}
-    Exit status is 0 if command was successful, and 1 if there was an error.
+    Exit status is 0 if command was successful. If wrong arguments are provided
+    or arguments contain errors, the script will exit early with exit status 1.
+
 "
 }
 
-if [[ ${1} == 'help' ]]
-then
-  __usage
-  exit 0
-fi
+function _parse_options
+{
+  while getopts ":yY" OPT
+  do
+    case "${OPT}" in
+      ( 'y' | 'Y' )
+        MAILDEL=1
+        ;;
 
-while getopts ":yYh" OPT
-do
-  case "${OPT}" in
-    ( 'y' | 'Y' )
-      MAILDEL=true
-      ;;
+      ( * )
+        __usage
+        _exit_with_error "The option '${OPT}' is unknown"
+        ;;
 
-    ( 'h' )
-      __usage
-      exit 0
-      ;;
+    esac
+  done
+}
 
-    ( * )
-      __usage
-      _exit_with_error "The option '${OPT}' is unknown"
-      ;;
+function _maildel_request_if_missing
+{
+  if [[ ${MAILDEL} -eq 0 ]]
+  then
+    local MAILDEL_CHOSEN
+    read -r -p "Do you want to delete the mailbox as well (removing all mails)? [Y/n] " MAILDEL_CHOSEN
 
-  esac
-done
+    # TODO: Why would MAILDEL be set to true if MAILDEL_CHOSEN is empty?
+    if [[ ${MAILDEL_CHOSEN} =~ (y|Y|yes|Yes) ]] || [[ -z ${MAILDEL_CHOSEN} ]]
+    then
+      MAILDEL=1
+    fi
+  fi
+}
+
+function _remove_maildir
+{
+  local MAIL_ACCOUNT=${1}
+
+  local LOCAL_PART="${MAIL_ACCOUNT%@*}"
+  local DOMAIN_PART="${MAIL_ACCOUNT#*@}"
+  local MAIL_ACCOUNT_STORAGE_DIR="/var/mail/${DOMAIN_PART}/${LOCAL_PART}"
+
+  [[ ! -d ${MAIL_ACCOUNT_STORAGE_DIR} ]] && _exit_with_error "Mailbox directory '${MAIL_ACCOUNT_STORAGE_DIR}' does not exist"
+
+  _log 'info' "Deleting Mailbox: '${MAIL_ACCOUNT_STORAGE_DIR}'"
+  rm -R "${MAIL_ACCOUNT_STORAGE_DIR}" || _exit_with_error 'Mailbox could not be deleted'
+  # Remove parent directory too if it's empty:
+  rmdir "/var/mail/${DOMAIN_PART}" &>/dev/null
+}
+
+# Support for optional maildir removal:
+MAILDEL=0
+_parse_options "${@}"
+# Remove options before passing over parameters to _main:
 shift $((OPTIND-1))
 
-[[ -z ${*} ]] && { __usage ; _exit_with_error 'No user specified' ; }
-[[ -s ${DATABASE} ]] || exit 0
-
-if ! ${MAILDEL}
-then
-  read -r -p "Do you want to delete the mailbox as well (removing all mails)? [Y/n] " MAILDEL_CHOSEN
-  if [[ ${MAILDEL_CHOSEN} =~ (y|Y|yes|Yes) ]] || [[ -z ${MAILDEL_CHOSEN} ]]
-  then
-    MAILDEL=true
-  fi
-fi
-
-_create_lock # Protect config file with lock to avoid race conditions
-
-for EMAIL in "${@}"
-do
-  ERROR=false
-
-  USER="${EMAIL%@*}"
-  DOMAIN="${EMAIL#*@}"
-
-  # ${EMAIL} must not contain /s and other syntactic characters
-  UNESCAPED_EMAIL="${EMAIL}"
-  EMAIL=$(_escape "${EMAIL}")
-
-  if [[ -f ${DATABASE} ]]
-  then
-    if ! sedfile --strict -i "/^${EMAIL}|/d" "${DATABASE}"
-    then
-      _log 'error' "'${UNESCAPED_EMAIL}' couldn't be deleted in '${DATABASE}'"
-      ERROR=true
-    fi
-  fi
-
-  if [[ -f ${ALIAS_DATABASE} ]]
-  then
-    # delete all aliases where the user is the only recipient( " ${EMAIL}" )
-    # delete user only for all aliases that deliver to multiple recipients ( ",${EMAIL}" "${EMAIL,}" )
-    if sed -i \
-      -e "/ ${EMAIL}$/d" -e "s/,${EMAIL}//g" -e "s/${EMAIL},//g" \
-      "${ALIAS_DATABASE}"
-    then
-      _log 'info' "'${UNESCAPED_EMAIL}' and potential aliases deleted"
-    else
-      _log 'error' "Aliases for '${UNESCAPED_EMAIL}' couldn't be deleted in '${ALIAS_DATABASE}'"
-      ERROR=true
-    fi
-  fi
-
-  # remove quota directives
-  if [[ -f ${QUOTA_DATABASE} ]]
-  then
-    if ! sedfile --strict -i -e "/^${EMAIL}:.*$/d" "${QUOTA_DATABASE}"
-    then
-      _log 'warn' "Quota for '${UNESCAPED_EMAIL}' couldn't be deleted in '${QUOTA_DATABASE}'"
-    fi
-  fi
-
-  if ! ${MAILDEL}
-  then
-    echo "Leaving the mailbox untouched.
-If you want to delete it at a later point,
-use 'sudo docker exec mailserver rm -R /var/mail/${DOMAIN}/${USER}'"
-    exit 0
-  fi
-
-  if [[ -e "/var/mail/${DOMAIN}/${USER}" ]]
-  then
-    if rm -R "/var/mail/${DOMAIN}/${USER}"
-    then
-      _log 'info' 'Mailbox deleted'
-    else
-      _log 'error' 'Mailbox could not be deleted'
-      ERROR=true
-    fi
-    rmdir "/var/mail/${DOMAIN}" &>/dev/null
-  else
-    log 'error' "Mailbox directory '/var/mail/${DOMAIN}/${USER}' did not exist"
-    ERROR=true
-  fi
-
-  ${ERROR} && _exit_with_error 'See the messages above.'
-done
-
-exit 0
+_main "${@}"
diff --git a/target/bin/delquota b/target/bin/delquota
index 1cd555db..47e89f57 100755
--- a/target/bin/delquota
+++ b/target/bin/delquota
@@ -3,20 +3,44 @@
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE='/tmp/docker-mailserver/dovecot-quotas.cf'
-USER_DATABASE='/tmp/docker-mailserver/postfix-accounts.cf'
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
 
-function __usage { echo 'Usage: delquota <username@domain>' ; }
+  local MAIL_ACCOUNT="${1}"
 
-[[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
+  _validate_parameters
+  _manage_dovecot_quota_delete "${MAIL_ACCOUNT}"
+}
 
-USER="${1}"
+function __usage
+{
+  printf '%s' "${PURPLE}delquota${RED}(${YELLOW}8${RED})
 
-[[ -z ${USER} ]] && { __usage ; _exit_with_error 'No username specified' ; }
-[[ ${USER} =~ .*\@.* ]] || { __usage ; _exit_with_error 'Username must include the domain' ; }
+${ORANGE}USAGE${RESET}
+    ./setup.sh quota del <MAIL ACCOUNT>
 
-grep -qE "^${USER}\|" "${USER_DATABASE}" || _exit_with_error "User '${USER}' does not exist"
+${ORANGE}OPTIONS${RESET}
+    ${BLUE}Generic Program Information${RESET}
+        help       Print the usage information.
 
-[[ -s ${DATABASE} ]] || exit 0
+${ORANGE}DESCRIPTION${RESET}
+    Remove any quota set for an existing mail account.
 
-sed -i -e "/^${USER}:.*$/d" "${DATABASE}"
+${ORANGE}EXAMPLES${RESET}
+    ${LWHITE}./setup.sh quota del user@example.com${RESET}
+
+${ORANGE}EXIT STATUS${RESET}
+    Exit status is 0 if command was successful. If wrong arguments are provided
+    or arguments contain errors, the script will exit early with exit status 1.
+
+"
+}
+
+function _validate_parameters
+{
+  _arg_expect_mail_account
+  _account_should_already_exist
+}
+
+_main "${@}"
diff --git a/target/bin/excluderelaydomain b/target/bin/excluderelaydomain
index bb5b6096..e4091dcf 100755
--- a/target/bin/excluderelaydomain
+++ b/target/bin/excluderelaydomain
@@ -3,17 +3,60 @@
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE='/tmp/docker-mailserver/postfix-relaymap.cf'
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
 
-DOMAIN="${1}"
+  local DOMAIN="${1}"
+  [[ -z ${DOMAIN} ]] && { __usage ; _exit_with_error 'No domain specified' ; }
 
-function __usage { echo 'Usage: excluderelayhost <domain>' ; }
+  _exclude_domain_from_relayhosts
+}
 
-[[ -z ${DOMAIN} ]] && { __usage ; _exit_with_error "no domain specified" ; }
+function __usage
+{
+  printf '%s' "${PURPLE}excluderelayhost${RED}(${YELLOW}8${RED})
 
-if grep -qi "^@${DOMAIN}" "${DATABASE}" 2>/dev/null
-then
-  sed -i "s/^@${DOMAIN}.*/@${DOMAIN}/" "${DATABASE}"
-else
-  echo -e "@${DOMAIN}" >> "${DATABASE}"
-fi
+${ORANGE}USAGE${RESET}
+    ./setup.sh relay exclude-domain <SENDER DOMAIN>
+
+${ORANGE}OPTIONS${RESET}
+    ${BLUE}Generic Program Information${RESET}
+        help       Print the usage information.
+
+${ORANGE}DESCRIPTION${RESET}
+    When a default relay-host is configured (via ENV), the default behaviour
+    is to relay all your mail accounts outgoing mail through that service.
+
+    This command allows to opt-out from that default behaviour by excluding
+    all mail accounts belonging to a hosted domain you specify.
+
+${ORANGE}EXAMPLES${RESET}
+    ${LWHITE}./setup.sh relay exclude-domain example.com${RESET}
+        Any mail submitted from your '@example.com' accounts will be sent
+        without relaying through a default relay-host (if one was configured).
+
+${ORANGE}EXIT STATUS${RESET}
+    Exit status is 0 if command was successful. If wrong arguments are provided
+    or arguments contain errors, the script will exit early with exit status 1.
+
+"
+}
+
+# Config is for sender dependent relay-host mapping,
+# excludes appending a sender from the real generated mapping in `helpers/relay.sh`.
+function _exclude_domain_from_relayhosts
+{
+  local SENDER="@${DOMAIN}"
+  local DATABASE_RELAY='/tmp/docker-mailserver/postfix-relaymap.cf'
+
+  # NOTE: No third arg is required.
+  # This won't cause any problems, a 'space' will be added with the key.
+  # That helps ensure repeat DB edits for the entry match correctly.
+  #
+  # `helpers/relay.sh` is also fine with this, and will eventually drop
+  # the need for this command entirely once that helper is refactored.
+  _db_entry_add_or_replace "${DATABASE_RELAY}" "${SENDER}"
+}
+
+_main "${@}"
diff --git a/target/bin/listalias b/target/bin/listalias
index 0eb90b40..f09643c9 100755
--- a/target/bin/listalias
+++ b/target/bin/listalias
@@ -3,10 +3,21 @@
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE='/tmp/docker-mailserver/postfix-virtual.cf'
+function _main
+{
+  local DATABASE_VIRTUAL='/tmp/docker-mailserver/postfix-virtual.cf'
+  _list_entries "${DATABASE_VIRTUAL}"
+}
 
-[[ -f ${DATABASE} ]] || _exit_with_error "No 'postfix-virtual.cf' file"
-[[ -s ${DATABASE} ]] || _exit_with_error "Empty 'postfix-virtual.cf' - no aliases have been added"
+function _list_entries
+{
+  local DATABASE=${1}
+  _db_should_exist_with_content "${DATABASE}"
 
-_get_valid_lines_from_file "${DATABASE}"
-exit 0
+  while read -r LINE
+  do
+    echo -e "* ${LINE}\n"
+  done < <(_get_valid_lines_from_file "${DATABASE}")
+}
+
+_main
diff --git a/target/bin/listdovecotmasteruser b/target/bin/listdovecotmasteruser
index d7766781..cf61555b 100755
--- a/target/bin/listdovecotmasteruser
+++ b/target/bin/listdovecotmasteruser
@@ -3,19 +3,24 @@
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-# suppress error output, e.g. when listmailuser runs in a fresh container (DMS not running)
-# shellcheck source=/dev/null
-source /etc/dms-settings 2>/dev/null
+function _main
+{
+  local DATABASE_DOVECOT_MASTERS='/tmp/docker-mailserver/dovecot-masters.cf'
+  _list_entries "${DATABASE_DOVECOT_MASTERS}"
+}
 
-DATABASE='/tmp/docker-mailserver/dovecot-masters.cf'
+function _list_entries
+{
+  local DATABASE=${1}
+  _db_should_exist_with_content "${DATABASE}"
 
-[[ -f ${DATABASE} ]] || _exit_with_error "No 'dovecot-masters.cf' file"
-[[ -s ${DATABASE} ]] || _exit_with_error "Empty 'dovecot-masters.cf' - no dovecot master accounts have been added"
+  local MASTER_ACCOUNT
+  while read -r LINE
+  do
+    MASTER_ACCOUNT=$(echo "${LINE}" | cut -d'|' -f1)
 
-while read -r LINE
-do
-  USER=$(echo "${LINE}" | cut -d'|' -f1)
-  echo "* ${USER}"
-done < <(_get_valid_lines_from_file "${DATABASE}")
+    echo -e "* ${MASTER_ACCOUNT}\n"
+  done < <(_get_valid_lines_from_file "${DATABASE}")
+}
 
-exit 0
+_main
diff --git a/target/bin/listmailuser b/target/bin/listmailuser
index 8dd7a0e4..0607b6cd 100755
--- a/target/bin/listmailuser
+++ b/target/bin/listmailuser
@@ -3,51 +3,103 @@
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-# suppress error output, e.g. when listmailuser runs in a fresh container (DMS not running)
+# Workaround to support ENABLE_QUOTAS toggling during tests:
 # shellcheck source=/dev/null
 source /etc/dms-settings 2>/dev/null
 
-function dovecot_quota_to_hr
+function _main
 {
-  if [[ ${1:-} == "-" ]]
+  local DATABASE_ACCOUNTS='/tmp/docker-mailserver/postfix-accounts.cf'
+  local DATABASE_VIRTUAL='/tmp/docker-mailserver/postfix-virtual.cf'
+
+  _list_entries "${DATABASE_ACCOUNTS}"
+}
+
+function _list_entries
+{
+  local DATABASE=${1}
+  _db_should_exist_with_content "${DATABASE}"
+
+  local ENTRY_TO_DISPLAY
+  while read -r LINE
+  do
+    ENTRY_TO_DISPLAY=$(_format_list_item "${LINE}")
+
+    echo -e "* ${ENTRY_TO_DISPLAY}\n"
+  done < <(_get_valid_lines_from_file "${DATABASE}")
+}
+
+function _format_list_item
+{
+  local LINE=${1}
+
+  local MAIL_ACCOUNT
+  MAIL_ACCOUNT=$(echo "${LINE}" | cut -d'|' -f1)
+
+  local WITH_QUOTA
+  WITH_QUOTA=$(_quota_show_for "${MAIL_ACCOUNT}")
+
+  local WITH_ALIASES
+  WITH_ALIASES=$(_alias_list_for_account "${MAIL_ACCOUNT}")
+
+  local ACCOUNT_ENTRY="${MAIL_ACCOUNT}"
+  [[ -n ${WITH_QUOTA}   ]] && ACCOUNT_ENTRY+=" ${WITH_QUOTA}"
+  [[ -n ${WITH_ALIASES} ]] && ACCOUNT_ENTRY+="\n    [ aliases -> ${WITH_ALIASES} ]"
+
+  echo "${ACCOUNT_ENTRY}"
+}
+
+function _quota_show_for
+{
+  local MAIL_ACCOUNT=${1}
+
+  [[ ${ENABLE_QUOTAS} -ne 1 ]] && return 0
+
+  local QUOTA_INFO
+  # Matches a line where the 3rd column is `type='STORAGE'` - returning the next three column values:
+  IFS=' ' read -r -a QUOTA_INFO <<< "$(doveadm quota get -u "${MAIL_ACCOUNT}" | tail +2 | awk '{ if ($3 == "STORAGE") { print $4" "$5" "$6 } }')"
+
+  local CURRENT_SIZE SIZE_LIMIT PERCENT_USED
+  # Format the extracted quota storage columns:
+  CURRENT_SIZE="$(_bytes_to_human_readable_size "${QUOTA_INFO[0]}")"
+  SIZE_LIMIT="$(_bytes_to_human_readable_size "${QUOTA_INFO[1]}")"
+  PERCENT_USED="${QUOTA_INFO[2]}%"
+
+  echo "( ${CURRENT_SIZE} / ${SIZE_LIMIT} ) [${PERCENT_USED}]"
+}
+
+function _bytes_to_human_readable_size
+{
+  # `-` represents a non-applicable value (eg: Like when `SIZE_LIMIT` is not set):
+  if [[ ${1:-} == '-' ]]
   then
-    echo "~"
+    echo '~'
+  # Otherwise a value in KibiBytes (1024 bytes == 1k) is expected (Dovecots internal representation):
   elif [[ ${1:-} =~ ^[0-9]+$ ]]
   then
+    # kibibytes to bytes, converted to approproate IEC unit (eg: MiB):
     echo $(( 1024 * ${1} )) | numfmt --to=iec
   else
-    _exit_with_error "Supplied non-number argument '${1:-}' to 'dovecot_quota_to_hr()' in script 'listmailuser'"
+    _exit_with_error "Supplied non-number argument '${1:-}' to '_bytes_to_human_readable_size()'"
   fi
 }
 
-DATABASE='/tmp/docker-mailserver/postfix-accounts.cf'
-ALIASES='/tmp/docker-mailserver/postfix-virtual.cf'
+# Returns a comma delimited list of aliases associated to a recipient (ideally the recipient is a mail account):
+function _alias_list_for_account
+{
+  local MAIL_ACCOUNT=${1}
 
-[[ -f ${DATABASE} ]] || _exit_with_error "No 'postfix-accounts.cf' file"
-[[ -s ${DATABASE} ]] || _exit_with_error "Empty 'postfix-accounts.cf' - no accounts have been added"
+  # `__db_list_already_contains_value` would be a more reliable check:
+  function _account_has_an_alias
+  {
+    local ANY_ALIAS='\S\+\s'
+    grep -qis "^${ANY_ALIAS}.*${MAIL_ACCOUNT}" "${DATABASE_VIRTUAL}"
+  }
 
-while read -r LINE
-do
-  USER=$(echo "${LINE}" | cut -d'|' -f1)
-
-  if [[ ${ENABLE_QUOTAS} -eq 1 ]]
+  if _account_has_an_alias
   then
-    # ${QUOTA[0]} => current size
-    # ${QUOTA[1]} => configured size limit
-    # ${QUOTA[2]} => usage in percent
-    IFS=' ' read -r -a QUOTA <<< "$(doveadm quota get -u "${USER}" | tail +2 | awk '{ if ($3 == "STORAGE") { print $4" "$5" "$6 } }')"
-    echo "* ${USER} ( $(dovecot_quota_to_hr "${QUOTA[0]}") / $(dovecot_quota_to_hr "${QUOTA[1]}") ) [${QUOTA[2]}%]"
-  else
-    echo "* ${USER}"
+    grep "${MAIL_ACCOUNT}" "${DATABASE_VIRTUAL}" | awk '{print $1;}' | sed ':a;N;$!ba;s/\n/, /g'
   fi
+}
 
-  if [[ -f ${ALIASES} ]] && grep -q "${USER}" "${ALIASES}"
-  then
-    echo -e "    [ aliases -> $(grep "${USER}" "${ALIASES}" | awk '{print $1;}' | sed ':a;N;$!ba;s/\n/, /g')]\n"
-  else
-    echo
-  fi
-done < <(_get_valid_lines_from_file "${DATABASE}")
-
-
-exit 0
+_main
diff --git a/target/bin/setquota b/target/bin/setquota
index beee5bbf..a230b2f5 100755
--- a/target/bin/setquota
+++ b/target/bin/setquota
@@ -1,43 +1,76 @@
 #! /bin/bash
 
-# ? This is done to ignore the message "Make sure not to read and write
-# ? the same file in the same pipeline", which is a result of ${DATABASE}
-# ? being used below. (This disables the message file-wide.)
-# shellcheck disable=SC2094
-
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE='/tmp/docker-mailserver/dovecot-quotas.cf'
-USER_DATABASE='/tmp/docker-mailserver/postfix-accounts.cf'
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
 
-USER="${1}"
-shift
-QUOTA="${*}"
+  local MAIL_ACCOUNT="${1}"
+  shift
+  local QUOTA="${*}"
 
-function __usage { echo 'Usage: setquota <user@domain> [<quota>]' ; }
+  _validate_parameters
+  _manage_dovecot_quota_update "${MAIL_ACCOUNT}" "${QUOTA}"
+}
 
-[[ -z ${USER} ]] && { __usage ; _exit_with_error "No username specified" ; }
-[[ ${USER} =~ .*\@.* ]] || { __usage ; _exit_with_error "Username must include the domain" ; }
+function __usage
+{
+  printf '%s' "${PURPLE}setquota${RED}(${YELLOW}8${RED})
 
-grep -qE "^${USER}\|" "${USER_DATABASE}" || _exit_with_error "User '${USER}' does not exist"
+${ORANGE}USAGE${RESET}
+    ./setup.sh quota set <MAIL ACCOUNT> [<QUOTA>]
 
-if [[ -z ${QUOTA} ]]
-then
-  read -r -s 'Enter quota (e.g. 10M): ' QUOTA
-  echo
-  [[ -z "${QUOTA}" ]] && _exit_with_error 'Quota must not be empty (use 0 for unlimited quota)'
-fi
+${ORANGE}OPTIONS${RESET}
+    ${BLUE}Generic Program Information${RESET}
+        help       Print the usage information.
 
-# check quota
-if ! grep -qE "^([0-9]+(B|k|M|G|T)|0)\$" <<< "${QUOTA}"
-then
-  __usage
-  _exit_with_error 'Invalid quota format. e.g. 302M (B (byte), k (kilobyte), M (megabyte), G (gigabyte) or T (terabyte))'
-fi
+${ORANGE}DESCRIPTION${RESET}
+    Set a quota (storage limit) for an existing mail account.
 
-_create_lock # Protect config file with lock to avoid race conditions
-touch "${DATABASE}"
+    The quota value is in bytes. You may use a unit suffix for convenience,
+    such as 10M for 10 MebiBytes (MiB). A value of 0 opts out of enforcing quota.
 
-delquota "${USER}"
-echo "${USER}:${QUOTA}" >>"${DATABASE}"
+${ORANGE}EXAMPLES${RESET}
+    ${LWHITE}./setup.sh quota set user@example.com 5G${RESET}
+        The account 'user@example.com' is restricted to a 5GiB storage limit.
+
+${ORANGE}EXIT STATUS${RESET}
+    Exit status is 0 if command was successful. If wrong arguments are provided
+    or arguments contain errors, the script will exit early with exit status 1.
+
+"
+}
+
+function _validate_parameters
+{
+  # MAIL_ACCOUNT
+  _arg_expect_mail_account
+  _account_should_already_exist
+
+  # QUOTA
+  _quota_request_if_missing
+  _quota_unit_is_valid
+}
+
+function _quota_request_if_missing
+{
+  if [[ -z ${QUOTA} ]]
+  then
+    read -r -p 'Enter quota (e.g. 10M): ' QUOTA
+    echo
+    [[ -z "${QUOTA}" ]] && _exit_with_error 'Quota must not be empty (use 0 for unlimited quota)'
+  fi
+}
+
+function _quota_unit_is_valid
+{
+  if ! grep -qE "^([0-9]+(B|k|M|G|T)|0)\$" <<< "${QUOTA}"
+  then
+    __usage
+    _exit_with_error 'Invalid quota format. e.g. 302M (B (byte), k (kilobyte), M (megabyte), G (gigabyte) or T (terabyte))'
+  fi
+}
+
+_main "${@}"
diff --git a/target/bin/updatedovecotmasteruser b/target/bin/updatedovecotmasteruser
index d228ec2d..b9628184 100755
--- a/target/bin/updatedovecotmasteruser
+++ b/target/bin/updatedovecotmasteruser
@@ -1,33 +1,45 @@
 #! /bin/bash
 
-# ? This is done to ignore the message "Make sure not to read and write
-# ? the same file in the same pipeline", which is a result of ${DATABASE}
-# ? being used below. (This disables the message file-wide.)
-# shellcheck disable=SC2094
-
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE=/tmp/docker-mailserver/dovecot-masters.cf
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
 
-USER="${1}"
-shift
-PASSWD="${*}"
+  local MAIL_ACCOUNT="${1}"
+  shift
+  local PASSWD="${*}"
 
-function __usage { echo 'Usage: updatedovecotmasteruser <USERNAME> [PASSWORD]' ; }
+  _manage_accounts_dovecotmaster_update "${MAIL_ACCOUNT}" "${PASSWD}"
+}
 
-[[ -z ${USER} ]] && { __usage ; _exit_with_error 'No username specified' ; }
+function __usage
+{
+  printf '%s' "${PURPLE}updatedovecotmasteruser${RED}(${YELLOW}8${RED})
 
-if [[ -z ${PASSWD} ]]
-then
-  read -r -s -p 'Enter Password: ' PASSWD
-  echo
-  [[ -z ${PASSWD} ]] && _exit_with_error 'Password must not be empty'
-fi
+${ORANGE}USAGE${RESET}
+    ./setup.sh dovecot-master update <MASTER ACCOUNT> [<PASSWORD>]
 
-HASH="$(doveadm pw -s SHA512-CRYPT -u "${USER}" -p "${PASSWD}")"
+${ORANGE}OPTIONS${RESET}
+    ${BLUE}Generic Program Information${RESET}
+        help       Print the usage information.
 
-touch "${DATABASE}"
-_create_lock # Protect config file with lock to avoid race conditions
-grep -qi "^$(_escape "${USER}")|" "${DATABASE}" 2>/dev/null || _exit_with_error "Master user \"${USER}\" does not exist"
-sed -i "s ^""${USER}""|.* ""${USER}""|""${HASH}"" " "${DATABASE}"
+${ORANGE}DESCRIPTION${RESET}
+    Update the password for a dovecot-master account.
+
+    To avoid a password being logged in the command history of your shell,
+    you may omit it, you'll be prompted to input the password instead.
+
+${ORANGE}EXAMPLES${RESET}
+    ${LWHITE}./setup.sh dovecot-master update example-account${RESET}
+        You will be prompted to input a password afterwards since no password was supplied.
+
+${ORANGE}EXIT STATUS${RESET}
+    Exit status is 0 if command was successful. If wrong arguments are provided
+    or arguments contain errors, the script will exit early with exit status 1.
+
+"
+}
+
+_main "${@}"
diff --git a/target/bin/updatemailuser b/target/bin/updatemailuser
index d43999c4..7a0d4075 100755
--- a/target/bin/updatemailuser
+++ b/target/bin/updatemailuser
@@ -1,33 +1,45 @@
 #! /bin/bash
 
-# ? This is done to ignore the message "Make sure not to read and write
-# ? the same file in the same pipeline", which is a result of ${DATABASE}
-# ? being used below. (This disables the message file-wide.)
-# shellcheck disable=SC2094
-
 # shellcheck source=../scripts/helpers/index.sh
 source /usr/local/bin/helpers/index.sh
 
-DATABASE='/tmp/docker-mailserver/postfix-accounts.cf'
+function _main
+{
+  [[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }
 
-USER="${1}"
-shift
-PASSWD="${*}"
+  local MAIL_ACCOUNT="${1}"
+  shift
+  local PASSWD="${*}"
 
-function __usage { echo 'Usage: updatemailuser <user@domain.tld> [password]' ; }
+  _manage_accounts_update "${MAIL_ACCOUNT}" "${PASSWD}"
+}
 
-[[ -z ${USER} ]] && { __usage ; _exit_with_error 'No username specified' ; }
+function __usage
+{
+  printf '%s' "${PURPLE}updatemailuser${RED}(${YELLOW}8${RED})
 
-if [[ -z ${PASSWD} ]]
-then
-  read -r -s -p 'Enter Password: ' PASSWD
-  echo
-  [[ -z ${PASSWD} ]] && _exit_with_error 'Password must not be empty'
-fi
+${ORANGE}USAGE${RESET}
+    ./setup.sh email update <MAIL ACCOUNT> [<PASSWORD>]
 
-HASH=$(doveadm pw -s SHA512-CRYPT -u "${USER}" -p "${PASSWD}")
+${ORANGE}OPTIONS${RESET}
+    ${BLUE}Generic Program Information${RESET}
+        help       Print the usage information.
 
-touch "${DATABASE}"
-_create_lock # Protect config file with lock to avoid race conditions
-grep -qi "^$(_escape "${USER}")|" "${DATABASE}" 2>/dev/null || _exit_with_error "User \"${USER}\" does not exist"
-sed -i "s ^""${USER}""|.* ""${USER}""|""${HASH}"" " "${DATABASE}"
+${ORANGE}DESCRIPTION${RESET}
+    Update the password for a mail account.
+
+    To avoid a password being logged in the command history of your shell,
+    you may omit it, you'll be prompted to input the password instead.
+
+${ORANGE}EXAMPLES${RESET}
+    ${LWHITE}./setup.sh email update user@example.com${RESET}
+        You will be prompted to input a password afterwards since no password was supplied.
+
+${ORANGE}EXIT STATUS${RESET}
+    Exit status is 0 if command was successful. If wrong arguments are provided
+    or arguments contain errors, the script will exit early with exit status 1.
+
+"
+}
+
+_main "${@}"
diff --git a/target/scripts/helpers/database/db.sh b/target/scripts/helpers/database/db.sh
new file mode 100644
index 00000000..990d0d2f
--- /dev/null
+++ b/target/scripts/helpers/database/db.sh
@@ -0,0 +1,213 @@
+#! /bin/bash
+
+# Matches relative path to this scripts parent directory,
+# Must be defined above any function that would source relative to it:
+# shellcheck source-path=target/scripts/helpers/database
+
+DMS_CONFIG='/tmp/docker-mailserver'
+# Modifications are supported for the following databases:
+#
+# Accounts and Aliases (The 'virtual' kind):
+DATABASE_ACCOUNTS="${DMS_CONFIG}/postfix-accounts.cf"
+DATABASE_DOVECOT_MASTERS="${DMS_CONFIG}/dovecot-masters.cf"
+DATABASE_VIRTUAL="${DMS_CONFIG}/postfix-virtual.cf"
+# Dovecot Quota support:
+DATABASE_QUOTA="${DMS_CONFIG}/dovecot-quotas.cf"
+# Relay-Host support:
+DATABASE_PASSWD="${DMS_CONFIG}/postfix-sasl-password.cf"
+DATABASE_RELAY="${DMS_CONFIG}/postfix-relaymap.cf"
+
+# Individual scripts with convenience methods to manage operations easier:
+function _db_import_scripts
+{
+  # This var is stripped by shellcheck from source paths below,
+  # like the shellcheck source-path above, it shouold match this scripts
+  # parent directory, with the rest of the relative path in the source lines:
+  local PATH_TO_SCRIPTS='/usr/local/bin/helpers/database'
+
+  source "${PATH_TO_SCRIPTS}/manage/dovecot-quotas.sh"
+  source "${PATH_TO_SCRIPTS}/manage/postfix-accounts.sh"
+  source "${PATH_TO_SCRIPTS}/manage/postfix-virtual.sh"
+}
+_db_import_scripts
+
+function _db_entry_add_or_append  { _db_operation 'append'  "${@}" ; } # Only used by addalias
+function _db_entry_add_or_replace { _db_operation 'replace' "${@}" ; }
+function _db_entry_remove         { _db_operation 'remove'  "${@}" ; }
+
+function _db_operation
+{
+  local DB_ACTION=${1}
+  local DATABASE=${2}
+  local KEY=${3}
+  # Optional arg:
+  local VALUE=${4}
+
+  # K_DELIMITER provides a match boundary to avoid accidentally matching substrings:
+  local K_DELIMITER KEY_LOOKUP
+  K_DELIMITER=$(__db_get_delimiter_for "${DATABASE}")
+  # Due to usage in regex pattern, KEY needs to be escaped:
+  KEY_LOOKUP="$(_escape "${KEY}")${K_DELIMITER}"
+
+  # Support for adding or replacing an entire entry (line):
+  # White-space delimiter should be written into DATABASE as 'space' character:
+  local V_DELIMITER="${K_DELIMITER}"
+  [[ ${V_DELIMITER} == '\s' ]] && V_DELIMITER=' '
+  local ENTRY="${KEY}${V_DELIMITER}${VALUE}"
+
+  # Support for 'append' + 'remove' operations on value lists:
+  # NOTE: Presently only required for `postfix-virtual.cf`.
+  local _VALUE_
+  _VALUE_=$(_escape "${VALUE}")
+  # `postfix-virtual.cf` is using `,` for delimiting a list of recipients:
+  [[ ${DATABASE} == "${DATABASE_VIRTUAL}" ]] && V_DELIMITER=','
+
+  # Perform requested operation:
+  if _db_has_entry_with_key "${KEY}" "${DATABASE}"
+  then
+    # Find entry for key and return status code:
+    case "${DB_ACTION}" in
+      ( 'append' )
+        __db_list_already_contains_value && return 1
+
+        sedfile --strict -i "/^${KEY_LOOKUP}/s/$/${V_DELIMITER}${VALUE}/" "${DATABASE}"
+        ;;
+
+      ( 'replace' )
+        ENTRY=$(__escape_sed_replacement "${ENTRY}")
+        sedfile --strict -i "s/^${KEY_LOOKUP}.*/${ENTRY}/" "${DATABASE}"
+        ;;
+
+      ( 'remove' )
+        if [[ -z ${VALUE} ]]
+        then # Remove entry for KEY:
+          sedfile --strict -i "/^${KEY_LOOKUP}/d" "${DATABASE}"
+        else # Remove target VALUE from entry:
+          __db_list_already_contains_value || return 0
+
+          # The delimiter between key and first value may differ from
+          # the delimiter between multiple values (value list):
+          local LEFT_DELIMITER="\(${K_DELIMITER}\|${V_DELIMITER}\)"
+          # If an entry for KEY contains an exact match for VALUE:
+          # - If VALUE is the only value => Remove entry (line)
+          # - If VALUE is the last value => Remove VALUE
+          # - Otherwise => Collapse value to LEFT_DELIMITER (\1)
+          sedfile --strict -i \
+            -e "/^${KEY_LOOKUP}\+${_VALUE_}$/d" \
+            -e "/^${KEY_LOOKUP}/s/${V_DELIMITER}${_VALUE_}$//g" \
+            -e "/^${KEY_LOOKUP}/s/${LEFT_DELIMITER}${_VALUE_}${V_DELIMITER}/\1/g" \
+            "${DATABASE}"
+          fi
+        ;;
+
+      ( * ) # Should only fail for developer using this API:
+        _exit_with_error "Unsupported DB operation: '${DB_ACTION}'"
+        ;;
+
+    esac
+  else
+    # Entry for key does not exist, DATABASE may be empty, or DATABASE does not exist
+    case "${DB_ACTION}" in
+      # Fallback action 'Add new entry':
+      ( 'append' | 'replace' )
+        [[ ! -d ${DMS_CONFIG} ]] && mkdir -p "${DMS_CONFIG}"
+        echo "${ENTRY}" >>"${DATABASE}"
+        ;;
+
+      # Nothing to remove, return success status
+      ( 'remove' )
+        return 0
+        ;;
+
+      ( * ) # This should not happen if using convenience wrapper methods:
+        _exit_with_error "Unsupported DB operation: '${DB_ACTION}'"
+        ;;
+
+    esac
+  fi
+}
+
+# Internal method for: _db_operation
+function __db_list_already_contains_value
+{
+  # Avoids accidentally matching a substring (case-insensitive acceptable):
+  # 1. Extract the current value of the entry (`\1`),
+  # 2. If a value list, split into separate lines (`\n`+`g`) at V_DELIMITER,
+  # 3. Check each line for an exact match of the target VALUE
+  sed -e "s/^${KEY_LOOKUP}\(.*\)/\1/" \
+      -e "s/${V_DELIMITER}/\n/g"      \
+      "${DATABASE}" | grep -qi "^${_VALUE_}$"
+}
+
+
+# Internal method for: _db_operation + _db_has_entry_with_key
+# References global vars `DATABASE_*`:
+function __db_get_delimiter_for
+{
+  local DATABASE=${1}
+
+  case "${DATABASE}" in
+    ( "${DATABASE_ACCOUNTS}" | "${DATABASE_DOVECOT_MASTERS}" )
+      echo "|"
+      ;;
+
+    # NOTE: These files support white-space delimiters, we have not
+    # historically enforced a specific value; as a workaround
+    # `_db_operation` will convert to ` ` (space) for writing.
+    ( "${DATABASE_PASSWD}" | "${DATABASE_RELAY}" | "${DATABASE_VIRTUAL}" )
+      echo "\s"
+      ;;
+
+    ( "${DATABASE_QUOTA}" )
+      echo ":"
+      ;;
+
+    ( * )
+      _exit_with_error "Unsupported DB '${DATABASE}'"
+      ;;
+
+    esac
+}
+
+# sed replacement feature needs to be careful of content containing `/` and `&`,
+# `\` can escape these (`/` exists in postfix-account.cf base64 encoded pw hash),
+# But otherwise care should be taken with `\`, which should be forbidden for input here?
+# NOTE: Presently only `.` is escaped with `\` via `_escape`.
+function __escape_sed_replacement
+{
+  # Matches any `/` or `&`, and escapes them with `\` (`\\\1`):
+  sed 's/\([/&]\)/\\\1/g' <<< "${ENTRY}"
+}
+
+#
+# Validation Methods
+#
+
+function _db_has_entry_with_key
+{
+  local KEY=${1}
+  local DATABASE=${2}
+
+  # Fail early if the database file exists but has no content:
+  [[ -s ${DATABASE} ]] || return 1
+
+  # K_DELIMITER provides a match boundary to avoid accidentally matching substrings:
+  local K_DELIMITER KEY_LOOKUP
+  K_DELIMITER=$(__db_get_delimiter_for "${DATABASE}")
+  # Due to usage in regex pattern, KEY needs to be escaped:
+  KEY_LOOKUP="$(_escape "${KEY}")${K_DELIMITER}"
+
+  # NOTE:
+  # --quiet --no-messages, only return a status code of success/failure.
+  # --ignore-case as we don't want duplicate keys that vary by case.
+  # --extended-regexp not used, most regex escaping should be forbidden.
+  grep --quiet --no-messages --ignore-case "^${KEY_LOOKUP}" "${DATABASE}"
+}
+
+function _db_should_exist_with_content
+{
+  local DATABASE=${1}
+
+  [[ -f ${DATABASE} ]] || _exit_with_error "'${DATABASE}' does not exist"
+  [[ -s ${DATABASE} ]] || _exit_with_error "'${DATABASE}' is empty, nothing to list"
+}
diff --git a/target/scripts/helpers/database/manage/dovecot-quotas.sh b/target/scripts/helpers/database/manage/dovecot-quotas.sh
new file mode 100644
index 00000000..3d783f50
--- /dev/null
+++ b/target/scripts/helpers/database/manage/dovecot-quotas.sh
@@ -0,0 +1,32 @@
+#! /bin/bash
+
+# Manage DB writes for: DATABASE_QUOTA
+
+# Logic to perform for requested operations handled here:
+function _manage_dovecot_quota
+{
+  local ACTION=${1}
+  local MAIL_ACCOUNT=${2}
+  # Only for ACTION 'update':
+  local QUOTA=${3}
+
+  local DATABASE_QUOTA='/tmp/docker-mailserver/dovecot-quotas.cf'
+  case "${ACTION}" in
+    ( 'update' )
+      _db_entry_add_or_replace "${DATABASE_QUOTA}" "${MAIL_ACCOUNT}" "${QUOTA}"
+      ;;
+
+    ( 'delete' )
+      _db_entry_remove "${DATABASE_QUOTA}" "${MAIL_ACCOUNT}"
+      ;;
+
+    ( * ) # This should not happen if using convenience wrapper methods:
+      _exit_with_error "Unsupported Action: '${ACTION}'"
+      ;;
+
+  esac
+}
+
+# Convenience wrappers:
+function _manage_dovecot_quota_update { _manage_dovecot_quota 'update' "${@}" ; } # setquota
+function _manage_dovecot_quota_delete { _manage_dovecot_quota 'delete' "${@}" ; } # delquota, delmailuser
diff --git a/target/scripts/helpers/database/manage/postfix-accounts.sh b/target/scripts/helpers/database/manage/postfix-accounts.sh
new file mode 100644
index 00000000..37ae1647
--- /dev/null
+++ b/target/scripts/helpers/database/manage/postfix-accounts.sh
@@ -0,0 +1,100 @@
+#! /bin/bash
+
+# Manage DB writes for:
+# - DATABASE_ACCOUNTS
+# - DATABASE_DOVECOT_MASTERS
+
+# Logic to perform for requested operations handled here:
+function _manage_accounts
+{
+  local ACTION=${1}
+  local DATABASE=${2}
+  local MAIL_ACCOUNT=${3}
+  # Only for ACTION 'create' or 'update':
+  local PASSWD=${4}
+
+  _arg_expect_mail_account
+
+  case "${ACTION}" in
+    ( 'create' | 'update' )
+      # Fail early before requesting password:
+      [[ ${ACTION} == 'create' ]] && _account_should_not_exist_yet
+      [[ ${ACTION} == 'update' ]] && _account_should_already_exist
+      _password_request_if_missing
+
+      local PASSWD_HASH
+      PASSWD_HASH=$(doveadm pw -s SHA512-CRYPT -u "${MAIL_ACCOUNT}" -p "${PASSWD}")
+      # Early failure above ensures correct operation => Add (create) or Replace (update):
+      _db_entry_add_or_replace "${DATABASE}" "${MAIL_ACCOUNT}" "${PASSWD_HASH}"
+      ;;
+
+    ( 'delete' )
+      _db_entry_remove "${DATABASE}" "${MAIL_ACCOUNT}"
+      ;;
+
+    ( * ) # This should not happen if using convenience wrapper methods:
+      _exit_with_error "Unsupported Action: '${ACTION}'"
+      ;;
+
+  esac
+}
+
+# Convenience wrappers:
+DATABASE_ACCOUNTS='/tmp/docker-mailserver/postfix-accounts.cf'
+function _manage_accounts_create { _manage_accounts 'create' "${DATABASE_ACCOUNTS}" "${@}" ; }
+function _manage_accounts_update { _manage_accounts 'update' "${DATABASE_ACCOUNTS}" "${@}" ; }
+function _manage_accounts_delete { _manage_accounts 'delete' "${DATABASE_ACCOUNTS}" "${@}" ; }
+
+# Dovecot Master account support can leverage the same management logic:
+DATABASE_DOVECOT_MASTERS='/tmp/docker-mailserver/dovecot-masters.cf'
+function _manage_accounts_dovecotmaster_create { _manage_accounts 'create' "${DATABASE_DOVECOT_MASTERS}" "${@}" ; }
+function _manage_accounts_dovecotmaster_update { _manage_accounts 'update' "${DATABASE_DOVECOT_MASTERS}" "${@}" ; }
+function _manage_accounts_dovecotmaster_delete { _manage_accounts 'delete' "${DATABASE_DOVECOT_MASTERS}" "${@}" ; }
+
+#
+# Validation Methods
+#
+
+# These validation helpers rely on:
+# - Exteral vars to be declared prior to calling them (MAIL_ACCOUNT, PASSWD, DATABASE).
+# - Calling external method '__usage' as part of error handling.
+
+# Also used by setquota, delquota
+function _arg_expect_mail_account
+{
+  [[ -z ${MAIL_ACCOUNT} ]] && { __usage ; _exit_with_error 'No account specified' ; }
+
+  # Dovecot Master accounts are validated (they are not email addresses):
+  [[ ${DATABASE} == "${DATABASE_DOVECOT_MASTERS}" ]] && return 0
+
+  # Account has both local and domain parts:
+  [[ ${MAIL_ACCOUNT} =~ .*\@.* ]] || { __usage ; _exit_with_error "'${MAIL_ACCOUNT}' should include the domain (eg: user@example.com)" ; }
+}
+
+function _account_should_not_exist_yet
+{
+  __account_already_exists && _exit_with_error "'${MAIL_ACCOUNT}' already exists"
+}
+
+# Also used by delmailuser, setquota, delquota
+function _account_should_already_exist
+{
+  ! __account_already_exists && _exit_with_error "'${MAIL_ACCOUNT}' does not exist"
+}
+
+function __account_already_exists
+{
+  local DATABASE=${DATABASE:-"${DATABASE_ACCOUNTS}"}
+  _db_has_entry_with_key "${MAIL_ACCOUNT}" "${DATABASE}"
+}
+
+# Also used by addsaslpassword
+function _password_request_if_missing
+{
+  if [[ -z ${PASSWD} ]]
+  then
+    read -r -s -p 'Enter Password: ' PASSWD
+    echo
+    [[ -z ${PASSWD} ]] && _exit_with_error 'Password must not be empty'
+  fi
+}
diff --git a/target/scripts/helpers/database/manage/postfix-virtual.sh b/target/scripts/helpers/database/manage/postfix-virtual.sh
new file mode 100644
index 00000000..caef1bd3
--- /dev/null
+++ b/target/scripts/helpers/database/manage/postfix-virtual.sh
@@ -0,0 +1,47 @@
+#! /bin/bash
+
+# Manage DB writes for: DATABASE_VIRTUAL
+
+# A virtual alias may be any of `user@domain`, `user`, `@domain`.
+# Recipients are local (internal services), hosted (managed accounts), remote (third-party MTA), or aliases themselves,
+# An alias may redirect mail to one or more recipients. If a recipient is an alias Postfix will recursively resolve it.
+#
+# WARNING: Support for multiple and recursive recipients may not be well supported by this projects scripts/features.
+# One of those features is Dovecot Quota support, which uses a naive workaround for supporting quota checks for inbound
+# mail to an alias address.
+
+# Logic to perform for requested operations handled here:
+function _manage_virtual_aliases
+{
+  local ACTION=${1}
+  local MAIL_ALIAS=${2}
+  local RECIPIENT=${3}
+
+  # Validation error handling expects that the caller has defined a '__usage' method:
+  [[ -z ${MAIL_ALIAS} ]] && { __usage ; _exit_with_error 'No alias specified'     ; }
+  [[ -z ${RECIPIENT}  ]] && { __usage ; _exit_with_error 'No recipient specified' ; }
+
+  local DATABASE_VIRTUAL='/tmp/docker-mailserver/postfix-virtual.cf'
+  case "${ACTION}" in
+    # Associate RECIPIENT to MAIL_ALIAS:
+    ( 'update' )
+      _db_entry_add_or_append "${DATABASE_VIRTUAL}" "${MAIL_ALIAS}" "${RECIPIENT}"
+      ;;
+
+    # Removes RECIPIENT from MAIL_ALIAS - or all aliases when MAIL_ALIAS='_':
+    # NOTE: If a matched alias has no additional recipients, it is also removed.
+    ( 'delete' )
+      [[ ${MAIL_ALIAS} == '_' ]] && MAIL_ALIAS='\S\+'
+      _db_entry_remove "${DATABASE_VIRTUAL}" "${MAIL_ALIAS}" "${RECIPIENT}"
+      ;;
+
+    ( * ) # This should not happen if using convenience wrapper methods:
+      _exit_with_error "Unsupported Action: '${ACTION}'"
+      ;;
+
+  esac
+}
+
+# Convenience wrappers:
+function _manage_virtual_aliases_update { _manage_virtual_aliases 'update' "${@}" ; } # addalias
+function _manage_virtual_aliases_delete { _manage_virtual_aliases 'delete' "${@}" ; } # delalias, delmailuser
diff --git a/target/scripts/helpers/index.sh b/target/scripts/helpers/index.sh
index 41d1b098..1136db16 100644
--- a/target/scripts/helpers/index.sh
+++ b/target/scripts/helpers/index.sh
@@ -19,6 +19,8 @@ function _import_scripts
   source "${PATH_TO_SCRIPTS}/relay.sh"
   source "${PATH_TO_SCRIPTS}/ssl.sh"
   source "${PATH_TO_SCRIPTS}/utils.sh"
+
+  source "${PATH_TO_SCRIPTS}/database/db.sh"
 }
 
 _import_scripts
diff --git a/test/tests.bats b/test/tests.bats
index e831b4f6..dcd71aca 100644
--- a/test/tests.bats
+++ b/test/tests.bats
@@ -599,7 +599,7 @@ EOF
 @test "checking accounts: user_without_domain creation should be rejected since user@domain format is required" {
   run docker exec mail /bin/sh -c "addmailuser user_without_domain mypassword"
   assert_failure
-  assert_output --partial "Username must include the domain"
+  assert_output --partial 'should include the domain (eg: user@example.com)'
 }
 
 @test "checking accounts: user3 should have been added to /tmp/docker-mailserver/postfix-accounts.cf" {