Failure in attempts to delete messages in Deleted Items Folder

[Robyn Raggio]

I am running Entourage 11.4.0 on my iMac with Leopard 10.5.8.
Whenever I try to delete messages out of the Deleted Items Folder, I
get the Error 4363 and the program crashes. Obviously there are a
thousands of messages, many with attachments that I am trying to
delete but all attempts are unsuccessful. I have reloaded a fresh
copy of the program, thinking there may be a glitch somewhere in the
alias. But it still doesn't function. I am reluctant to rebuild as
the folders I have as projects I don't want to lose.

Any suggestions?

Thanks for your time and your assistance,

Robyn