553 Attack detected from pool

[majdi]

One of our email users keeps getting the email below, I’m not sure what’s causing this has anyone had this message before?

----- Original Message -----
From: "Mail Delivery Subsystem @localhost.domain" <MAILER-DAEMON>
To: "User Name" <user@my-domain>
Sent: Tuesday, November 27, 2007 8:37 AM
Subject: Returned mail: see transcript for details


The original message was received at Tue, 27 Nov 2007 08:37:14 +0300
from localhost [127.0.0.1]

----- The following addresses had permanent fatal errors -----
<engcv@gulfskilled.com>
(reason: 553 Attack detected from pool 213.210.252.36.
<http://unblock.secureserver.net/?ip=213.210.252.*>)

----- Transcript of session follows -----
... while talking to smtp.secureserver.net.:
>>> RCPT To:<engcv@gulfskilled.com>
<<< 553 Attack detected from pool 213.210.252.36.
<http://unblock.secureserver.net/?ip=213.210.252.*>
550 5.1.1 <engcv@gulfskilled.com>... User unknown

[andreasb]

Hi there,

this just means, that the administrator or provider operating the mailserver for "afi.com.sa" is using a blacklist to validate his emails (see http://unblock.secureserver.net/ ). But on this blacklist the whole ip range 213.210.252.* seems to be blocked. Your mailserver seems to be within that range .

Try to find out what is wrong at http://unblock.secureserver.net/ or try to contact the operator of this blacklist.

[majdi]

Thanks I'll check this out.