Univention Bugzilla – Bug 57084
Mail relay host configuration insufficient
Last modified: 2024-02-26 11:52:29 CET
## Story As a administrator, I can get all necessary information from our UCS manual, so that I can configure a mail relay host with e.g. port 587 that requires authentication. ## Context/description The UCS manual about how to configure a mail relay host is a little bit sparse and does not contain the interesting parts for relay hosts on non-default-ports (465 or 587). Additionally it is not stated how the credentials have to be defined in /etc/postfix/smtp_auth if non standard ports are used. ### Technical details / new content for manual: - `mail/relayhost` There are 2 (4) possible formats to specify the relay host: - `ucr set mail/relayhost="mx01.example.com"` Outgoing mail is delivered to the mailserver mx01.example.com on port 25. - `ucr set mail/relayhost="mx01.example.com:587"` Outgoing mail is delivered to the mailserver mx01.example.com on port 587. Please note, that postfix is doing a DNS lookup on `mx01.example.com` for the MX/SRV entry to determine the actual target address. If you are unsure, that this means, please use the following notation to avoid misrouted e-mails. - `ucr set mail/relayhost="[mx01.example.com]"` Outgoing mail is delivered to the mailserver mx01.example.com on port 25. - `ucr set mail/relayhost="[mx01.example.com]:587"` Outgoing mail is delivered to the mailserver mx01.example.com on port 587. - `/etc/postfix/smtp_auth` Credentials for outgoing mailservers have to be written into the file `smtp_auth`. The usual format is `mailserver username:password`. The `mailserver` part should look exactly like the setting that is done in the UCRV `smtp/relayhost`, e.g. `[mx01.example.com]:587 outgoing@subdomain.example.com:verySecretPassword`, otherwise postfix might not use credentials for the relay host at all.