Once in a while, Outlook refuses to send a message after clicking Send and instead returns the error, "Internal Application Error." If we then try to save the message, we get the same error message. (Fortunately, we can copy and paste the text of the message into another application so that it can be saved.)

Rebooting the computer fixes the problem.

I'm just wondering if anyone knows what could cause "internal application errors" in Outlook. I'd like to prevent these errors if I can.

We are using NT Workstations and Exchange Server.