Set Postfix to disconnect before queuing all recipients

I don't know anything about iRedMail, but my guess would be that it has configured Postfix to do content scanning during the incoming SMTP transaction. If so, Postfix can't close the connection early because the client will have no idea whether the message was successfully delivered.

For a standard Postfix install, I would look at the configuration and move any intensive content-scanning activities to occur after a message is accepted.

However, web control panels like to do things their own way, and tend not to behave well when manual configuration changes are made. I would suggest asking in the iRedMail forums rather than here.

Thanks for the suggestion Vance.

I should have mentioned that I have already disabled content/virus scanning. Policyd is still configured though. I think I will try using port 587 specifically, the client is set for automatic port selection right now and could be using 25. And yes I will post in the iredmail forums. Thanks for the link.

Pokey

@Pokey:

I should have mentioned that I have already disabled content/virus scanning.
Hmm, not sure where else to point you. It's possible you're using DNS block lists that are slow to respond or not responding at all. But usually there's a timeout set up so that if it can't contact a particular DNSBL after a few seconds, it just proceeds as if no negative response was received.

Yes, you were on the right track. I got the suggestion from the iRedmail forums to remove "rejectunknownrecipient_domain" from the postfix conf.

Thanks.

Thanks for letting us know the solution. It'll help anyone with the same problem who comes across this thread.