Corrupt queue files with Postfix

[Nick Slager]

We're running Mailscanner 4.28.5 and Postfix 2.0.16 on FreeBSD. The system
has been set up with two Postfix instances, as detailed at
http://www.sng.ecs.soton.ac.uk/mailscanner/install/postfix.shtml.

Mailscanner works great, however, we're encountering a problem where sometimes
the outgoing Postfix instance complains of corrupt queue files after
Mailscanner has injected them into the queue:

Mar 10 10:16:37 host postfix/smtp[66320]: warning: corrupted queue file: active/60914A198C
Mar 10 10:17:05 host postfix/smtp[66329]: warning: corrupted queue file: active/875D0A19B5
Mar 10 10:17:30 host postfix/smtp[66369]: warning: corrupted queue file: active/C4387A18EC
Mar 10 10:18:00 host postfix/smtp[66341]: warning: corrupted queue file: active/51BCDA187E

These messages are reasonably frequent - we're seeing 2-3000 per day.

The Postfix documentation states that corrupted queue files are moved to
the 'corrupt' queue (/var/spool/postfix/corrupt); however, these queue
files are simply disappearing. They do not exist anywhere in the
filesystem.

While there appears to be an anomaly with Postfix, resulting in these
queue files disappearing, I'm more concerned with why the files have been
corrupted by Mailscanner in the first place.

Analysing the logs shows that (so far without exception) each message is
in fact infected with a variant of the new NetSky virus. As a result I
haven't been too concerned with the fact that the messages are being
corrupted and subsequently disappearing.

However, obviously it would be far better if the messages were not being
corrupted by MailScanner.

Can anyone shed any light on why the messages are being corrupted, and how
to stop it occuring?

cheers,



Nick