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<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=656494416-19102007>Were
lots of the messages undeliverable messages?</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=656494416-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=656494416-19102007>In
which case it could be your domain was under a backscatter attack see -
</SPAN></FONT><FONT face=Arial color=#0000ff size=2><SPAN
class=656494416-19102007><A
href="http://spamlinks.net/prevent-secure-backscatter.htm">http://spamlinks.net/prevent-secure-backscatter.htm</A></SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=656494416-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=656494416-19102007>Ive
had this happen to various customers where all of a sudden there incommg e-mail
shoots up to ridiculous levels.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=656494416-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=656494416-19102007>The
quickest form of defence would be to implement some sort of recipient
verification - I use mimedefang to achieve this here (sendmail). Before sendmail
accepts the e-mail it checks if the recipient is indeed a valid user on your
exchange box.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=656494416-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=656494416-19102007>You
need to be running at least Exchange 2003 and above and enable recipient
filtering <A
href="http://support.microsoft.com/kb/886208">http://support.microsoft.com/kb/886208</A></SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=656494416-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=656494416-19102007>If the
messages were not lots of undeliverable messages and all to valid recipients I
would agree with the other reply that your server sounds like it needs an
upgrade to cope.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=656494416-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=656494416-19102007>Cheers</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=656494416-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=656494416-19102007>Paul</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=656494416-19102007></SPAN></FONT> </DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px solid">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B>
mailscanner-bounces@lists.mailscanner.info
[mailto:mailscanner-bounces@lists.mailscanner.info]<B>On Behalf Of
</B>Gareth<BR><B>Sent:</B> 19 October 2007 17:32<BR><B>To:</B> MailScanner
discussion<BR><B>Subject:</B> RE: Weird Problem with MailScanner {Scanned by
Allteks Mailsafe}<BR><BR></FONT></DIV>
<DIV><SPAN class=544243116-19102007><FONT face=Arial color=#0000ff size=2>I
would say it is seriously in need of a memory upgrade. The minimum
recomendation is 1GB.</FONT></SPAN></DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px solid; MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B>
mailscanner-bounces@lists.mailscanner.info
[mailto:mailscanner-bounces@lists.mailscanner.info]<B>On Behalf Of
</B>Damian Rivas<BR><B>Sent:</B> 19 October 2007 17:22<BR><B>To:</B>
mailscanner@lists.mailscanner.info<BR><B>Subject:</B> Weird Problem with
MailScanner<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>Hi there, I'm
having a really weird problem and as I am a n00b it gets a bit more
difficult to find a solution. </SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=725004715-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>I'll explain the
details first:</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=725004715-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>Since 6 months
ago, I am the System Administrator of a Tourism Agency. We use an E-mail
Scanner in a server with the following characteristics:</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=725004715-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>Processor:
Pentium II 233 Mhz.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>RAM: 128
MB</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>OS: Linux
Slackware 9</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>MailScanner
version: 4.55.10</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=725004715-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>This E-mail
Scanner use the MailScanner with Sophos Antivirus and Spam Assasin to filter
spam and scan incoming and outcoming mails for viruses which are then
redirected to an internal MS Exchange Server or to the Internet,
respectively by sendmail.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=725004715-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>One month
ago, the server started behaving erratically. Instead of checking
and sending mails as it normally did, it started queueing mails massively
and therefore accumulating great quantities of them, it got up to 10000
mails queued up in a single day, therefore, no one recieved a single
mail. After many pointless attempts to repair this problem and seeing that
the Travel Agents were getting a bit mad, I decided to redirect the MX
server of our domains in the DNS to the firewall, so that our E-Mail Scanner
server didn't recieve more mail, which was only going to contribute to
making the problem worse, more incoming mails, more queued
mails.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=725004715-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>With this, the
server started sending the queued mails and mail traffic was restored
with the difference that mails weren't scanned at all(they were no longer
passing through the MailScanner Server). When the mail queues were empty
again, I tried to reestablish the scanning service, but the problem appeared
again.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=725004715-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>I don't have a
clear idea of what can be causing this problem. The machine is pretty old,
but the former administrator told me that it had never had problems. I think
that perhaps we are being Spam Bombed and perhaps the System poor processing
capabilities cannot resists the increasing traffic and therefore it gets
stuck and keeps enqueueing mails.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=725004715-19102007></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>Please if anyone
can guide me I'll appreciate it,</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>Sorry if my
English is a bit rusty, it is not my native language, therefore if you need
me to be more clear or try to give more details of something, don't hesitate
to ask so.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=725004715-19102007>Thanks in
advance!</SPAN></FONT></DIV>
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