Question : Message queue  que.dat keeps regenerating spam

I am Running Exchange 5.5. and NT 4 Sp6a.
A clients echange server has been hijacked for spamming due to poor setup of relay option.
This is now secure.
There are however still 1000 messages in the outbound mail queue.
I can stop the mail service and delete the file que.dat, but as soon as I start the mail service again the que.dat file grows to 112MB and the same 1000 spam messages appear in the outbound mail que.
The server is  not connected to the internet at this point.
How can I stop this.
I have scanned for all virus and worms nothing found.

any help greatly appreciated.

Answer : Message queue  que.dat keeps regenerating spam

Are you using IMS?  

If so you may want to remove the IMS connector.  Delete the queue files and reinstall the connector.  Remember to secure relaying if you do this as I goofed and forgot to secure it once.  Late night mind was a little fuzzy.

Joe