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Exchange server bandwidth hog

Last Modified: 2008-01-25
Hey Guys,

I have a big of a funny one and I am not sure how to further trouble shoot it. I have a Windows Server 2003 enviroment and I have a Front end and Back end Exchange 2003 SP2 setup. Almost every morning for the last few weeks the front end server creates so much outbound smtp traffic that my line to the internet chokes. I have checked the Que during this time and found only a few (maybe 10) messages ready for delivery. The outbound traffic (all on port 25) is active for about 10-15 mins and then it is gone and we do not have a problem for the rest of the day. I have checked the logs and found no problems in the event logs.
Watch Question

Is it possible you have a virus somewhere on your network which could be causing SMTP traffic to increase??? have you increased your logging levels for SMTP connectors to see if you can capture a better debug output.


Sorry I was on vacation and then I setup some software to gather data on the problem. What I have found is that when emails with large attachments are sent is when we have the problem. Is their any way to limit the rate that exchange send out email?
yes.  create a policy to size limit send and recieve for smtp mail data


the linkwill show you how


Its not so much the size of the messages that we are trying to send we have a 10mb limit on messages. The problem that I am having comes from if we send out a message with a 3mb attachment, the exchange server delivers that message as fast as it possibly can and in doing so it saturates the upload bandwidth on our DSL connection. I am looking for a way to limit the packet stream to less then 256kbps or something like that. Just to keep it from saturating the line for the rest of the users.
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I have found that we are able to do rate limiting with our Firewall to help even out the about of bandwidth the SMTP box can use.
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