diff --git a/docs/content/config/environment.md b/docs/content/config/environment.md
index 5a9963ac..293fe861 100644
--- a/docs/content/config/environment.md
+++ b/docs/content/config/environment.md
@@ -51,6 +51,8 @@ User provisioning via OIDC is planned for the future, see [this tracking issue](
 - OIDC => use OIDC authentication (**not yet implemented**)
 - FILE => use local files (this is used as the default)
 
+A second container for the ldap service is necessary (e.g. [docker-openldap](https://github.com/osixia/docker-openldap))
+
 ##### PERMIT_DOCKER
 
 Set different options for mynetworks option (can be overwrite in postfix-main.cf) **WARNING**: Adding the docker network's gateway to the list of trusted hosts, e.g. using the `network` or `connected-networks` option, can create an [**open relay**](https://en.wikipedia.org/wiki/Open_mail_relay), for instance if IPv6 is enabled on the host machine but not in Docker.
@@ -208,7 +210,7 @@ Enabled by ENABLE_POSTFIX_VIRTUAL_TRANSPORT. Specify the final delivery of postf
 
 - **empty**: fail
 - `lmtp:unix:private/dovecot-lmtp` (use socket)
-- `lmtps:inet:<host>:<port>` (secure lmtp with starttls, take a look at <https://sys4.de/en/blog/2014/11/17/sicheres-lmtp-mit-starttls-in-dovecot/>)
+- `lmtps:inet:<host>:<port>` (secure lmtp with starttls)
 - `lmtp:<kopano-host>:2003` (use kopano as mailstore)
 - etc.
 
diff --git a/mailserver.env b/mailserver.env
index 18b20027..85e134f9 100644
--- a/mailserver.env
+++ b/mailserver.env
@@ -181,7 +181,7 @@ ENABLE_POSTFIX_VIRTUAL_TRANSPORT=
 #
 # empty => fail
 # `lmtp:unix:private/dovecot-lmtp` (use socket)
-# `lmtps:inet:<host>:<port>` (secure lmtp with starttls, take a look at https://sys4.de/en/blog/2014/11/17/sicheres-lmtp-mit-starttls-in-dovecot/)
+# `lmtps:inet:<host>:<port>` (secure lmtp with starttls)
 # `lmtp:<kopano-host>:2003` (use kopano as mailstore)
 # etc.
 POSTFIX_DAGENT=
@@ -333,7 +333,6 @@ FETCHMAIL_POLL=300
 # -----------------------------------------------
 
 # A second container for the ldap service is necessary (i.e. https://github.com/osixia/docker-openldap)
-# For preparing the ldap server to use in combination with this container this article may be helpful: http://acidx.net/wordpress/2014/06/installing-a-mailserver-with-postfix-dovecot-sasl-ldap-roundcube/
 
 # with the :edge tag, use ACCOUNT_PROVISIONER=LDAP
 # empty => LDAP authentification is disabled