MAILER-DAEMON loop?

I’ve recently seen some spam with bad return addresses trigger an
email loop where the autoreply gets a ‘No such recipient’ error
back which then sends a new response to the requestor at the
same address. I think RT already has some logic to detect this
since I haven’t seen it often, but shouldn’t any message from
‘MAILER-DAEMON’ be a special case that doesn’t send email in
response?

Les Mikesell
les@futuresource.com