1.8 KiB
| title |
|---|
| Override the Default Configs | Postfix |
Our default Postfix configuration can easily be extended to add parameters or modify existing ones by providing a docker-data/dms/config/postfix-main.cf. This file uses the same format as Postfix main.cf does (See official docs for all parameters and syntax rules).
!!! example "Example"
One can easily increase the [backwards-compatibility level](http://www.postfix.org/postconf.5.html#compatibility_level) and set new Postscreen options:
```cf
# increase the compatibility level from 2 (default) to 3
compatibility_level = 3
# set a threshold value for Spam detection
postscreen_dnsbl_threshold = 4
```
!!! help "How are your changes applied?"
The custom configuration you supply is appended to the default configuration located at `/etc/postfix/main.cf`, and then `postconf -nf` is run to remove earlier duplicate entries that have since been replaced. This happens early during container startup before Postfix is started.
Similarly, it is possible to add a custom docker-data/dms/config/postfix-master.cf file that will override the standard master.cf. Note: Each line in this file will be passed to postconf -P, i.e. the file is not appended as a whole to /etc/postfix/master.cf like docker-data/dms/config/postfix-main.cf! The expected format is <service_name>/<type>/<parameter>, for example:
# adjust the submission "reject_unlisted_recipient" option
submission/inet/smtpd_reject_unlisted_recipient=no
!!! attention There should be no space between the parameter and the value.
Run postconf -Mf in the container without arguments to see the active master options.