On Fri, 9 Jun 2023, Sean Gallagher wrote:
It feels like you are conflating Dovecot with Postfix. Dovecot doesn't actually "relay" anything. (ignoring sieve and submission proxy). Relaying is the job of the "Mail Transfer Agent" or MTA. This is often Postfix but Dovecot could probably work with just about any standards-compliant mailer.
If your system is acting as an open relay, you need to look at your MTA configuration.
You should probably try the Postfix mailing list. Try the "postfix-users" list. https://www.postfix.org/lists.html
Thanks Sean,
The relaying only started and stopped when Dovecot was turned on or off.
Isn't it true that Dovecot performs an authentication function for inbound connect requests, the successful of which then may use the submission mechanism from what Postfix takes to be an internal connection to send emails? Is this mistaken?
However, I get your point and I've spent a lot of work on that area. And, you may well be right that that's where I need to turn - that is, to Postfix. Thanks for the link.
Richard