>Upon further investigation, the majority of the inbound emails are to invalid 
>addresses at our domain.  We have a backup mail service and in talking to them 
>they say they are getting upwards of 66,000 emaills an hour for our domain 
>during the time our server is out of service.

Sounds like a joe-job/backscatter or malicious attack.

One of the most appreciated values of IMGate is that it blocks all msgs to 
unknown recipients before they can overload the IMail server.  Unknown 
recipients is typically 50% of all traffic arriving at the MX.  Then 
greylisting blocks another 40% from hitting the Imail server.  Envelope 
policies and content-scanning handle the rest so that well 10% of MX traffic 
actually arrives at Imail.

 From your report, it sounds like Imail 10 still can't handle high-volume 
attacks.  66000/3600 = about 20 msgs/second.


IMGate OpenSource Mail Firewall www.IMGate.net

To Unsubscribe: http://imailserver.com/support/discussion_list/
List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/
Knowledge Base/FAQ: http://imailserver.com/support/kb.html

Reply via email to