MailScanner SPAM Forward & Postfix Problem

Drew Marshall drew at THEMARSHALLS.CO.UK
Thu Apr 7 16:44:42 IST 2005

    [ The following text is in the "iso-8859-1" character set. ]
    [ Your display is set for the "US-ASCII" character set.  ]
    [ Some characters may be displayed incorrectly. ]

Kennedy Clark said:
> I installed MailScanner/SpamAssassin/ClamAV last week.  I used Johnny
Hughes' excellent guide at
> (see Part 4).
> I'm using RHEL 3/CentOS 3.4.  On the MTA side, I am using Postfix with a
virtual alias table.  I want to have MailScanner use the "forward" "Spam
Actions" option to put all spam in a central email account (it's a local
account on the same server).  I can email to this central spam account
no problem (both locally and from outside accounts such as gmail).  The
"Spam Actions = forward blah at" works if
> blah at is an account on a separate system (such as this account
on gmail).   However, no matter what I do, I cannot make it work with a
local account -- I always get the following postfix error in
> /var/log/maillog:
>   ..., status=bounced (user unknown in virtual alias table).
> I'm guessing it has something to do with the fact that I'm using a
virtual alias table, but I don't want to get rid of that (even for
testing purposes) because it's obviously being used for live email. :-)

This is a Postfix err, 'feature'. Because of the way that Postfix and
MailScanner work, you can't forward spam to a virtual user.

The why: Postfix uses the cleanup agent to do the virtual aliasing,
unfortunately this happens _before_ MailScanner sees the message. So when
you re-inject a spam message to a virtual user, it's after Postfix would
have alised it to it's real destination, hence the bounce.

The solution: Forward spam to a local account that is alised to your
virual user e.g. forward spam to localuser at box.domain.tld then in the
aliases table put localuser: virtual at virtual.tld and then $newaliases

That will then do the job for you.



In line with our policy, this message has
been scanned for viruses and dangerous
content by MailScanner, and is believed to be clean.

------------------------ MailScanner list ------------------------
To unsubscribe, email jiscmail at with the words:
'leave mailscanner' in the body of the email.
Before posting, read the MAQ ( and
the archives (

Support MailScanner development - buy the book off the website!

More information about the MailScanner mailing list