[Rspamd-Users] First Time: DKIM Signing Only

[Gerald Galster]

>> ... is there some way I can pass in an argument via sendmail that I
>> can use to identify outbound mailing list messages? If so, I could
>> use that to enable DKIM signing and ideally DMARC munging as well.
> 
> Presumably your mailing list software adds headers to mail it sends
> out.  Could they not identify your "outbound mailing list messages"?
> 
> If I understand what you want, then if I were doing this I'd just look
> for the list header with a milter and sign it if the header is there.

Depending on your setup that could be a simple solution but you should
make sure that mails with non-mailinglist origin do not contain that
header. Otherwise this could lead to rspamd signing unwanted mails.

As not all headers are considered for dkim-signing it might be
possible to remove that line with (milter_)header_checks and the
IGNORE action.

https://www.postfix.org/postconf.5.html#header_checks
https://www.postfix.org/postconf.5.html#milter_header_checks
https://www.postfix.org/header_checks.5.html

Best regards,
Gerald