SMTP & Exchange Server flood

[hobbzilla]

We use Exchange for pretty much local use only. Clients use Outlook 2k & 2k3.

Exchange is not setup to be a SPAM relay.. nor does the router allow incoming port forwarding to the Exchange box. (Clients get e-mail via a POP3 linux server due to the free spam software installed -- which then get's imported into their Exchange store once Outlook downloads them).

Anyway, a local user tried sending out an e-mail to a 150 or so people with attachements of about 3.5MB. Shortly after this all users were complaining of network slowness and some sites would time-out. After investigating I found the problem to be the Exchange server flooding the switch & router. After going through the lists of services.. stopping SMTP made the problem dissappear. I cleared the SMTP Queue and restarted the service. The messages simply came back again. The user that sent the mail is getting undeliverable reports and continues to recieve them even after receiving over the 150 she has sent. Now they are coming back "Delayed". Is there a way to remove the Exchange Outgoing messages while the SMTP service is down? If I shut down SMTP and clear the queue.. they simply come back again to try again!?!

Any help would be greatly appreciated! I don't know why they are bouncing back in the first place -- so perhaps that would be a better solution.

[MadDog]

You'll need to leave all the services running. Launch Exchange System Manager and navigate to [server name]/Protocols/SMTP/Queues (may be slightly different depending on your version of Exchange). From there you can search the queues for the message by subject (Exchange 2003) or go to each domain queue and manually delete the e-mail causing the problem (Exchange 2000/5.5).

3.5MB may be over the maximum message size of the recipient's server... Check the code at the bottom of the NDR.