Blocking top-level domains

[Bryan Laurila]

I had an interesting situation creep up on me this week where I thought
that something was happening (or being processed) in
MailScanner/SpamAssassin but apparently it was not.

I have two mail relay scanners running MailScanner & SpamAssassin on
Suse Linux.  These boxes scan incoming mail for spam & viruses and then
relay to my MS Exchange server.  I had an influx of spam this week
coming in from several top-level domains that we wouldn't normally
receive any valid emails from anyway, like .eu, .in, .asia, .club, etc.


Upon investigating the situation I found that the Trend Micro Scan Mail
service on my Exchange server crashed which lead me to the discovery
that MailScanner & SpamAssassin weren't filtering mail from these
unwanted top level domains as I thought and all that work was being done
by my exchange server.

So, the question of the day is...  Where is the best place to turn on
filtering or set a rule somehow to filter unwanted top-level domains at
the MailScanner/SpamAssassin servers?

Like all things in IT there are probably multiple ways of doing this so
I am curious as to what others are doing.  All thoughts & comments are
welcome.

Thanks!

Bryan S. Laurila
Senior Network Support Analyst
Dickinson County Healthcare System
1721 South Stephenson Avenue
Iron Mountain, Michigan 49801

"Life begins at the end of your comfort zone!"




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Dickinson County Healthcare System, 1721 S. Stephenson Ave. Iron Mountain, MI 49801, www.dchs.org
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