Had this issue also.  Very unfun.  Imail appears not to handle this phenomenon 
particularly well.  Quickfix is to write a little cmd or bat file on a schedule 
or to be called when an external program, like Server's Alive, senses too many 
files in the queue.  Called a 'GSE killer'

e:
cd \imail\spool
del *.gse

Depending upon your architecture (like if you are using gatewayed domains), 
this issue is additionally exasperated by even a small  dictionary attack.  A 
dictionary attack also adds to the number of postmaster bounces, if you are not 
rejecting at the envelope right on the MX.  If your server is barely hanging on 
trying to deliver postmaster bounces, a dict attack can then render it 
impotent.     

For the real fix, from our experience, v8.x definitely appears to handle this 
sort of thing more elegantly using 'queue manager'.      
  

Dave

  



-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of David Delbridge
Sent: Sunday, February 27, 2005 9:55 AM
To: [email protected]
Subject: [IMail Forum] Postmaster DOS


Hi all,

My IMail 7.1 server is experiencing a recurring denial-of-service or 
failure situation.  After watching the server for two weeks now, a 
couple of symptoms have caught my eye:

1.) IMail appears to be 'hanging' on a particular message, indicated by 
a '~' GSE or SMD file in the queue which never goes away.

2.) A large number (hundreds) of GSE files.  It appears that a number of 
client inboxes are full and that a preponderance of 'mailbox full' 
auto-replies from the postmaster to non-existent spam addresses or 
spoofed virus source addresses is racking up lots of bogus outbound mail 
which cannot be delivered.  Of course, this might not be a cause, but 
instead an effect of the server hanging up.

3.) Deleting the GSE and '~' files while restarting the SMTP service 
appears to fix the problem, but only temporarily.  In another few days, 
the server will be hung up again.

What is odd is that the SMTP service appears to be completely log-jammed 
by this situation, rather than attempting delivering of new mail before 
dumping failed deliveries to the queue for retrying.  Everything is 
going straight to the queue.

Any ideas?

Thank you very much!

ps.  I am using IMail 7.1, Declude Anti-Spam and Declude Anti-Virus, 
with F-Prot.  I did recently install another general-purpose McAfee 
virus scanner and then removed it when these troubles started, thinking 
that the scanner might be quarantining files while Declude/F-Prot was 
analyzing them.  But then, the troubles never completely went away.

Dave

-- 

David M. Delbridge
Circa 3000
ColdFusion Hosting
http://www.circa3k.com
866-CIRCA3K (247-2235)
Outside U.S: +1.775-832-2445


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