Question : Problem: SMTP server causing network to slow dramatically and ping times to go over 1000+ ms

I'm running Exchange Server 2003 on W2K3 Server. Server is not an open relay, but over the last few days I started getting ping times of 500-1500 ms and the mail queues started to fill up. It used to be intermittent, but now the long ping times are constant if the smtp server is running and consequently the whole network starts to bog down. As soon as the service is stopped the ping times return to normal, between 12-24 ms. I now have a few hunderd pieces of mail in the queues. They're good addresses but stuck because of the activity once the smtp server is started and the ping response spikes to 1000+ ms which is causing smtp connections to fail and generate some 7004 event id's.  Any help would be greatly appreciated.

Answer : Problem: SMTP server causing network to slow dramatically and ping times to go over 1000+ ms

Refer http://objectmix.com/microsoft-exchange/267005-exchange-2003-errors-event-id-4006-7002-7004-a.html - see if the solution helps.

There is a way to manage connections on Exchange allowing you to set the amount of messages being sent out at any given time.  Check server set up as per - http://technet.microsoft.com/en-us/library/aa996805(EXCHG.65).aspx and see if you can reduce the number of connections that the server handles at any given time - http://technet.microsoft.com/en-us/library/bb123637(EXCHG.65).aspx