Re: [fw-wiz] Cisco PIX Version 6.3(3) SMTP Problem

From: Paul D. Robertson (paul_at_compuwar.net)
Date: 07/06/05

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    To: "David M. Nicksic" <dnicksic@mossbaygroup.com>
    Date: Wed, 6 Jul 2005 08:51:15 -0400 (EDT)
    
    

    On Tue, 5 Jul 2005, David M. Nicksic wrote:

    > I am using a PIX 520 v 6.3.3 and having a spam problem. A spam service
    > Postini is employed. I want to deny all SMTP traffic unless it comes from
    > one of the Postini servers. Can the PIX be configured to accomplish this?
    >

    Almost any firewall can, however you'll be out of e-mail if the provider
    has to put up a new server because of an attack, failure, problem or
    address change. It's probably better to configure your mail server to
    reject based on forward/reverse lookups, since you're dealing with one
    zone, you'll be able to cache the lookups pretty well.

    Note that Postini rejects mail if your server isn't reachable by it- so
    it's not all that resilient if you're under attack or having server
    issues[1]. Personally, I'd rather run Mailscanner on a Postfix instance
    than
    outsource something as critical as e-mail.

    Paul
    [1] Theoretically most things will retry, but you may want to test
    critical pager/cell/alert stuff to make sure it won't just give up if
    you're under conditions where contacting you becomes important.
    -----------------------------------------------------------------------------
    Paul D. Robertson "My statements in this message are personal opinions
    paul@compuwar.net which may have no basis whatsoever in fact."
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