Queue filling up

[Sunvest]

My Queue in Exchange 2003 keeps filling up with "delivery stautus notification (failure)" from my own postmaster. These are directed to really odd email addresses. Is someone trying to relay through my server? Has anyone ever had this problem before? Any help would be greatly appreciated. If any further info would help i can supply it.

Thanks

 

[xmsre]

From RFC 3464: DSNs may be forged as easily as ordinary Internet electronic mail. User agents and automatic mail handling facilities (such as mail distribution list exploders) that wish to make automatic use of DSNs should take appropriate precautions to minimize the potential damage from denial-of-service attacks.

That's an NDR flood attack. What can you do? In Exchange 2003, see

http://support.microsoft.com/kb/842851/en-us