Mailing List Message #92875
From: Matthew Black <>
Subject: Re: Hotmail issue
Date: Mon, 08 Oct 2007 13:02:11 -0700
To: CommuniGate Pro Discussions <>
X-Mailer: CommuniGate Pro WebUser v5.0.9
We hear this problem frequently and these two questions
are likely answer why:

Is your hosted customer per chance sending SMTP messages
directly to Hotmail rather than THROUGH your CGP system?

Is your CGP system running on a dynamic DSL connection
or have you purchased a fixed IP address with both
forward and reverse DNS service? What is returned from
both forward and reverse nslookup queries? Have you
ensured your CGP server's IP address is not listed
in the Spamhaus SBL?

matthew black
california state university, long beach

On Mon, 08 Oct 2007 06:31:21 -0700
 "Hisham Al Saad" <> wrote:

One of our hosted customers when ever tries to send email to Hotmail, his
messages bounces with below reply. He is connecting from a dynamic IP,
however we have many customers connecting the same way with no problems.
This message was created automatically by mail delivery software.

A message that you sent could not be delivered to all of its recipients.

following address(es) failed:

The reason for failure was as follows:

550 Mail rejected by Windows Live Hotmail for policy reasons. We

generally do not accept email from dynamic IP's as they are not typically

used to deliver unauthenticated SMTP email to an Internet mail server. maintains lists of dynamic and residential IP

addresses. Contact your ISP to determine which authorized SMTP relay

to send your mail through (or) request a static and dedicated IP before

attempting to send mail. For additional information about Microsoft's

technical guidelines, please refer to:

Any hints please what causes this.


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