Question Safe to enable postgrey with free Plesk Email Security (Amavis + SpamAssassin + ClamAV)?

[Jürgen_T]

Server operating system version

Ubuntu 22.04.5 LTS

Plesk version and microupdate number

Plesk Obsidian v18.0.68_build1800250319.12 os_Ubuntu 22.04

Hi everyone,
I'm running a Plesk server using the free Plesk Email Security extension, which includes Amavis and SpamAssassin. I’ve also installed ClamAV manually, and it's working perfectly within the current mail pipeline.
To further reduce spam and bot traffic, I now plan to add Greylisting via postgrey.
Here’s the setup:

• Mail server: Postfix
• Content filter: smtp-amavis:[127.0.0.1]:10024 (unchanged)
• No Rspamd in use
• Greylisting configuration (planned):

smtpd_recipient_restrictions =
permit_mynetworks,
permit_sasl_authenticated,
check_policy_service inet:127.0.0.1:10023,
reject_unauth_destination

postgrey will be limited to unauthenticated external traffic, and I’ll monitor logs closely. Everything else, including Amavis and ClamAV, should remain untouched.


❓ Are there any known conflicts or caveats when using postgrey alongside Plesk’s free mail security stack (Amavis + SpamAssassin + ClamAV)?
Any experience or advice would be much appreciated before I go ahead.


Thanks a lot in advance!

 

[ChristophRo]

caveats?
long delivery delays for inbound messages and you'll need to closely monitor the mail flow and manage the ever increasing whitelist for your Postgrey daemon.
the practical benefit of greylisting is also pretty much non-existing nowadays...

IMHO you're better off implementing Postscreen on your server.
Similar approach and usefulness as greylisting, but less intrusive and with near zero caveats.