NOTE: This method is called only if you
implemented IwodPop3Notify interface in your application,
and wodPop3Server1.Notification
property has received reference to
instance of your implementation.
This notification method is called after user issues
'QUIT' command and is about to leave server.
At this time, you should not try to examine contents of
messages or any information about user. Although you'll
find them in User parameter - you should have done it
already before in UpdateMailbox
notification. This notification method is strictly
informational.