spam forwarding not working

[Nigel Kendrick]

Hi guys,

I have setup a spam mailbox on our local mail server that users can submit
their unwanted stuff to - it's called 'spam@[snipped]'

The 'spam' mailbox is submitted to spamassassin every night via a cron job.
This works with no problems for mail that people manually forward, but I
also have this line in MailScanner.conf:

High Scoring Spam Actions = delete forward spam@[snipped]

Unfortunately, this triggers the following emails to me (at root):

++++++++++

This is the Postfix program at ...

I'm sorry to have to inform you that your message could not be delivered to
one or more recipients. It's attached below.

[Snip]

<spam@[snipped]>: User unknown in virtual alias table

++++++++++

I have also tried local delivery by putting the forward address as
'spam at servername' - am I hitting problems because spam is being resubmitted
to MailScanner before being forwarded, but even then why a 'user unknown'
message?

MailScanner is 4.55.10, PostFix is 2:2.2.10-1.RHEL4.2 on CentOS 4.4

Thanks

Nigel Kendrick