Yes, the DELE commands are in the connection log. The problem may be that Bounce Handler is not the only application accessing the mailbox.
We get legitimate email at the same address as the sender of the bulk mail. By making the return-path, from, and reply-to all the same (that is, a legitimate email address), we've found that we can avoid spam filters much more effectively.
My problem is basically this:
1) I send out the bulk message in the evening before I leave for the day.
2) I have Bounce Handler scheduled every twenty minutes.
3) The next morning, I open my email to find hundreds of bounces mixed in with normal responses to the message.
I was hoping that Bounce Handler would remove the bounces from the server, thereby preventing my normal email program from needlessly downloading a bunch of bounces.