can you determine the IP(s) that the dictionary attacks are coming from?  If so, block 
them altogether?



> -----Original Message-----
> From: Dave Strzemienski [mailto:[EMAIL PROTECTED]
> Sent: Thursday, March 11, 2004 10:12 AM
> To: [EMAIL PROTECTED]
> Subject: [IMail Forum] Bounce to forged From address blacklisted my
> server
> 
> 
> I recently set up an IMail/mxGuard/ClamAV server that sits in 
> front of my
> corporate email server.
> It's been running for several days and has reduced the amount 
> of incoming
> spam & viruses about 95% according to my users.
> 
> But, I've now discovered that this new server is listed on 
> bl.spamcop.net.
> 
> As far as I can tell, this is how it happened:
> 
> Spammer forges the Mail-From address on a piece of junkmail and
> dictionary-attacks my domains.
> My intercept server processes & attempts to forward the 
> message to user(s)
> that don't exist on the corporate server.
> The corporate server informs the intercept server that the 
> user(s) don't
> exist and does not accept the message.
> The intercept server bounces the message to the forged 
> Mail-From address.
> The Mail-From address that was forged by the spammer is 
> actually a Spam
> Trap.
> The Spam Trap server informs spamcop.net that my intercept 
> server is sending
> messages with spam content.
> 
> Is there anything I can do about this?
> 
> I was going to set up a nobody alias, but I started receiving 
> upwards of
> 10,000 messages a hour and my server slowed to a crawl.  And 
> that was just
> for one domain.
> 
> Any help is appreciated!
> Dave Strzemienski
> 
> 
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