I had an email hit my server Friday that crashed my server. Every time i brought it back up it would almost instantaneously crash. Didn't know what was causing it at first, but deleting the mail.box before restarting solved the problem until it crashed an hour later. I finally tracked it down after I saw that they had resent a message!
The NSD yielded :
Panic: Lookuphandle not allocated.
The attachment has a .jpg and 2 .pdf files. I cannot reproduce this on a 6.0 server.
Very frustrated that any mail message would take the server down!