Qmail and misdirected bounces

[moltar]

I am just wondering if the qMail version that is shipped with Plesk 7.5 Reloaded is suffering from this as well?

Is it safe to apply any of the below patches/fixes to the Plesk's version of qMail?

SpamCop released a warning about the following problem:

Problem: Misdirected bounces
Description: When a mail server accepts a message and later decides that it can't deliver the message, it is required to send back a bounce email to the sender of the original message. These bounce emails are often misdirected.
Solution: Upgrade and/or configure your mail server software so that this situation is never encountered. Configure your software to either reject messages during delivery or accept them permanently. Do not let your software make choices about delivery after it has accepted a message. If you must accept delivery before you know the status of a message, then file it internally - do not send, forward or bounce it outside your organization. The errant message can be placed in a special folder or routed to your postmaster.

Avoid offloading your filtering task onto random third parties. You must filter your own mail, not ask others to do it for you.

Qmail:
Qmail is one popular mail exchanger which suffers from this problem by default. If you use qmail, please apply a patch: spamcontrol or qmail-ldap.
There is also an experimental patch for qmail which allows you to send bounces, but isolate them on a different IP address (so that spamcop can block them without blocking other mail): Richard Lyons' BOUNCEQUEUE patch

John Simpson has provided a set of qmail patches that enjoy wide distribution. Check out qmail validrcptto.cdb Patch

PZInternet.com reports chkuser is a very good qmail patch to avoid misdirected bounces - very easy to install too! http://www.interazioni.it/opensource/chkuser/

For users of qmail-toasters, check out the simscan patch

 

[SecondPhase]

CHKUSER

Anybody a reply to this, my qmail (plex 7.5.4/fedora 2) is not checking recipient upon connection. Seems to do ok detecting bad bounce and trashing the message but i think this issue needs to be addressed.

I looked into the chkuser patch described above and it looks like a good mainstream solution for us..

Has anybody tried it? Does anyone know if it will work with the plesk qmail set up? or how to apply the patch?

Check it out. Thanks!

 

[SecondPhase]

Reject Option in Plesk 7.5

Hey there, i found that indeed Plesk 7.5 does have a Reject option that can be selected instead of Bounce at the Domain -> Mail -> Preferences.

This option does reportedly interfere with Mailman however. see related thread in the suggestions forum. i think it's going to work for me since i don't need mailman at the moment that much.. and can look for a patch for that later..

Cheers