Hi,

Yeah that is a problem with vanishing messages.  Something for all 
admins to consider.  It can go on for quite sometime before someone 
realises sometimes too.

A nice post.

Regards,
Stuart

On 2/03/2011 8:39 a.m., surgemailHIDDEN@etwinsite.com wrote:
> Just wanted to you all know about a situation that we have just resolved...
>
> Starting mid February we started getting reports/complaints about
> missing email. After about two weeks a pattern started to emerge that
> indicated it was Telus Communications that was causing our grief.
> Finally last week another complaint come in that indicated the same
> situation was happening with Shaw Communications customers. Expanding
> our search and contacts I found that I could not get anywhere with Shaw
> or Telus front end support.
>
> So far all we knew was that message to us, and from us were vanishing
> once they left our servers.
>
> Late last week I got a "final" message from Shaw saying they wouldn't
> help out anymore and that we were to get the recipients of the missing
> messages to submit messages to a not spam email address to resolve the
> issue.
>
> I located the phone number to Shaw (I'm a customer of their's but the
> College is not) and called their head office. Turns out that was the
> right move, they put me in touch with someone that took the lead and
> "caught the bull by the horns". As it turns out Shaw confirmed that our
> phone number (the one listed in my signature) had been identified as a
> spam fingerprint in the Cloudmark anti-spam device's network.
>
> It seems that there is a botnet out there that is spamming users and
> that spam has our phone number listed in it. As a result, users were
> submitting that spam and the Cloudmark network started silently deleting
> messages with our phone number in it. Shaw managed to open a ticket with
> Cloudmark and escalate the removal of our phone number from their
> database. Finally were sending again.
>
> It just struck me though as really difficult to get to the bottom of the
> issue and that this can be used as a form of denial of service. We did
> nothing, but our messages were being deleted silently without notice to
> anyone!
>
>
> Kevin W. Gagel
> Network Administrator
> College of New Caledonia
> (250)562-2131 local 5448
>
>
>
>
>
>
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