How about restricting mail system administration to not allow entry of
nobody aliases?  Should be some simple javascript additions to handle this.

Darin.


----- Original Message ----- 
From: "Robert E. Spivack" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, September 19, 2006 12:48 PM
Subject: [IMail Forum] Comcast mail blocking - diagnosis and request for
help disabling aliases/forwarding


Like others here, we have seen one of our mail servers blocked from
sending email to Comcast with the rejection message of spam not allowed.

After extensive monitoring, I believe I have tracked down the root
cause.  We have a few users that had a "nobody" alias configured on
their domain with a forwarding rule sending all incoming email to
Comcast.

They also had turned off all their spam filtering.  The result is that
dictionary-attack type spam was being accepted by their incoming mailbox
(because of the "nobody" alias) and then forwarded to Comcast.

Because of the presumably multiple emails forwarded to Comcast from the
same account/mail server, it was triggering spam detection filters on
Comcast end.

Unfortunately it would appear that Comcast (like AOL) does not
distinguish between the real source of the email and the unfortunate
victim (our mail server/stupid user).

I have taken remedial steps for this user (deleting their "nobody" alias
and disabling their mail forwarding to Comcast.

I'm looking for an automated method to enforce these restrictions
(disallow nobody alias, disallow forwarding to Comcast or aol addresses)
server-wide and was wondering what is the best way to do this?

Two possible solutions:

Some kind of batch file process that scans the IMail registry entries
and deletes nobody entries and changes rules that forward to Comcast/aol
to forward to null, or --

Setting up another server as a gateway for outbound mail and somehow
implementing these restrictions on the gateway (and then setting the
other mail servers to use the gateway as the smarthost for all outbound
mail delivery.)

Hopefully, some of you have already implemented something like this and
can provide guidance and assistance.

TIA
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