diff --git a/Makefile b/Makefile
index 05029946..aed0b797 100644
--- a/Makefile
+++ b/Makefile
@@ -9,6 +9,7 @@ build:
 run:
 	# Copy test files
 	cp test/accounts.cf postfix/
+	cp test/main.cf postfix/
 	cp test/virtual postfix/
 	# Run containers
 	docker run -d --name mail \
@@ -18,6 +19,7 @@ run:
 		-e SA_TAG=1.0 \
 		-e SA_TAG2=2.0 \
 		-e SA_KILL=3.0 \
+		-e SASL_PASSWD=testing \
 		-h mail.my-domain.com -t $(NAME)
 	docker run -d --name mail_pop3 \
 		-v "`pwd`/postfix":/tmp/postfix \
@@ -36,11 +38,11 @@ run:
 
 fixtures:
 	# Sending test mails
-	docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/test/email-templates/amavis-spam.txt"		
-	docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/test/email-templates/amavis-virus.txt"		
-	docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/test/email-templates/existing-alias-external.txt"		
-	docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/test/email-templates/existing-alias-local.txt"		
-	docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/test/email-templates/existing-user.txt"		
+	docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/test/email-templates/amavis-spam.txt"
+	docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/test/email-templates/amavis-virus.txt"
+	docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/test/email-templates/existing-alias-external.txt"
+	docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/test/email-templates/existing-alias-local.txt"
+	docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/test/email-templates/existing-user.txt"
 	docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/test/email-templates/non-existing-user.txt"
 	# Wait for mails to be analyzed
 	sleep 10
@@ -51,6 +53,6 @@ tests:
 
 clean:
 	# Get default files back
-	git checkout postfix/accounts.cf postfix/virtual
+	git checkout postfix/accounts.cf postfix/main.cf postfix/virtual
 	# Remove running test containers
 	docker rm -f mail mail_pop3 mail_smtponly
diff --git a/README.md b/README.md
index 0cd895f9..6fdb8edf 100644
--- a/README.md
+++ b/README.md
@@ -97,6 +97,9 @@ Example:
   * *6.31* (default) => add 'spam detected' headers at that level
 * SA_KILL
   * *6.31* (default) => triggers spam evasive actions)
+* SASL_PASSWORD
+  * *empty* (default) => No sasl_passwd will be created
+  * *string* => A /etc/postfix/sasl_passwd will be created with that content and postmap will be run on it
 
 Please read [how the container starts](https://github.com/tomav/docker-mailserver/blob/master/start-mailserver.sh) to understand what's expected.  
 
diff --git a/postfix/master.cf b/postfix/master.cf
index 8804f632..b2fe0de9 100644
--- a/postfix/master.cf
+++ b/postfix/master.cf
@@ -72,6 +72,7 @@ smtp-amavis     unix    -       -       -       -       2       smtp
   -o smtp_send_xforward_command=yes
   -o disable_dns_lookups=yes
   -o max_use=20
+  -o smtp_tls_security_level=none
 
 127.0.0.1:10025 inet    n       -       n       -       -       smtpd
   -o content_filter=
@@ -92,3 +93,4 @@ smtp-amavis     unix    -       -       -       -       2       smtp
   -o smtpd_client_connection_count_limit=0
   -o smtpd_client_connection_rate_limit=0
   -o receive_override_options=no_header_body_checks,no_unknown_recipient_checks
+  -o smtp_tls_security_level=none
diff --git a/postfix/opendkim.conf b/postfix/opendkim.conf
index 05c9d340..f8c1b6c3 100644
--- a/postfix/opendkim.conf
+++ b/postfix/opendkim.conf
@@ -4,6 +4,7 @@ UMask                   002
 Syslog                  yes
 SyslogSuccess           Yes
 LogWhy                  Yes
+RemoveOldSignatures	Yes
 
 Canonicalization        relaxed/simple
 
@@ -18,4 +19,4 @@ SignatureAlgorithm      rsa-sha256
 
 UserID                  opendkim:opendkim
 
-Socket                  inet:12301@localhost
\ No newline at end of file
+Socket                  inet:12301@localhost
diff --git a/start-mailserver.sh b/start-mailserver.sh
index e8668a36..46f1ff45 100644
--- a/start-mailserver.sh
+++ b/start-mailserver.sh
@@ -196,6 +196,26 @@ case $DMS_SSL in
 
 esac
 
+if [ -f /tmp/postfix/main.cf ]; then
+  while read line; do
+    postconf -e "$line"
+  done < /tmp/postfix/main.cf
+  echo "Loaded '/tmp/postfix/main.cf'"
+else
+  echo "'/tmp/postfix/main.cf' not provided. No extra postfix settings loaded."
+fi
+
+if [ ! -z "$SASL_PASSWD" ]; then
+  echo "$SASL_PASSWD" > /etc/postfix/sasl_passwd
+  postmap hash:/etc/postfix/sasl_passwd
+  rm /etc/postfix/sasl_passwd
+  chown root:root /etc/postfix/sasl_passwd.db
+  chmod 0600 /etc/postfix/sasl_passwd.db
+  echo "Loaded SASL_PASSWORD"
+else
+  echo "==> Warning: 'SASL_PASSWORD' is not provided. /etc/postfix/sasl_passwd not created."
+fi
+
 echo "Fixing permissions"
 chown -R 5000:5000 /var/mail
 mkdir -p /var/log/clamav && chown -R clamav:root /var/log/clamav
diff --git a/test/main.cf b/test/main.cf
new file mode 100644
index 00000000..37155392
--- /dev/null
+++ b/test/main.cf
@@ -0,0 +1,2 @@
+max_idle = 600s
+readme_directory = /tmp
diff --git a/test/tests.bats b/test/tests.bats
index be681fb1..8cfe488e 100644
--- a/test/tests.bats
+++ b/test/tests.bats
@@ -105,6 +105,11 @@
   [ "$status" -eq 0 ]
 }
 
+@test "checking sasl: sasl_passwd.db exists" {
+  run docker exec mail [ -f /etc/postfix/sasl_passwd.db ]
+  [ "$status" -eq 0 ]
+}
+
 #
 # smtp
 #
@@ -217,6 +222,13 @@
   [ "${lines[1]}" = "otherdomain.tld" ]
 }
 
+@test "checking postfix: main.cf overrides" {
+  run docker exec mail grep -q 'max_idle = 600s' /tmp/postfix/main.cf
+  [ "$status" -eq 0 ]
+  run docker exec mail grep -q 'readme_directory = /tmp' /tmp/postfix/main.cf
+  [ "$status" -eq 0 ]
+}
+
 #
 # spamassassin
 #