Large numbers of "Undelivered Mail Returned to Sender" messages to admin

[OverZealous]

With the new onslaught of viruses that my Zimbra server has been getting, I started getting a ton of undelivered notices in my Admin account. I already found the option to prevent backscatter in the admin, which cut them by half, however I still get a message for every virus that looks like this:

From:		MAILER-DAEMON@mail.example.com
Subject:	Undelivered Mail Returned to Sender
Date:		September 7, 2008 6:56:21 PM GMT-04:00
To:		admin@mailserver.example.com
<NOTE: the differing servers is not an accident, but the accounts are set up correctly>

This is the mail system at host mail.example.com...
<snipped boilerplate "could not be delivered" text>

<admin@mailserver.example.com>: mailserver.example.com
Reporting-MTA: dns; mail.example.com
Original-Envelope-Id: AM.......@mail.example.com
X-Postfix-Queue-ID: 71FF762E835
X-Postfix-Sender: rfc822; admin@mailserver.example.com
Arrival-Date: Sun,  7 Sep 2008 18:56:21 -0400 (EDT)

Final-Recipient: rfc822; admin@mailserver.example.com
Original-Recipient: rfc822;admin@mailserver.example.com
Action: failed
Status: 5.0.0
Diagnostic-Code: X-Postfix; mailserver.example.com

<original message then follows, with virus warning>

I can send a message to that account without error. It is just an alias for my account. Today alone I've received this message 14 times - which isn't a ton, but annoying none-the-less.

Is there something I can do to alleviate this? I've searched the forums, and there doesn't appear to be anyone else with this exact problem.

Thanks!

[alto]

I'm afraid I cannot offer any help on this, just to add that I am getting the same type of email. Even set up a filter to direct them to trash, can get 20+ a day. Just annoying really and would really like to reduce them.

Undelivered Mail Returned to Sender

This is the mail system at host removed this

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

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

The mail system

[alto]

Any ideas?

Could it be stopped by editing master.cf in postfix changing the line below

notify_classes=bounce,resource,software

But to what????

170 of these undelivered over the last 5 days