Your message dated: Thu, 08 May 1997 12:52:41 MDT

> Once again, why add extra load to your system by bouncing instead of
> canning them.

    One problem:

    How do you, a priori, determine whether a particular mail message
is legitimate or junk?  If there was a way to do that, we'd simply
never accept any junk in the first place, and guarantee that all
the mail we did accept was "legitimate".  Then, any bounces we'd
have to generate would be only for "legitimate" mail that was sent
to users who don't exist anymore, who have full mailboxes, etc....


    However, that is impossible.

    One of the very few things you can do is determine whether
or not a message is correctly formed, and syntactically valid.
You can choose to reject the others, or try to fix them if you like.


    On this basis, we have a particular type of "incorrectly formed"
messages that we choose to refuse to accept.  Unfortunately, a very
small percentage of them are legitimate, but we have no a priori
way of knowing that.

    The only option available to us in this situation is to refuse
them all, and provide enough information in our rejection message
that those few who are attempting to send legitimate messages will
hopefully get their systems fixed.

--
Brad Knowles                                MIME/PGP: [log in to unmask]
    Senior Unix Administrator              <http://www.his.com/~brad/>
<http://swissnet.ai.mit.edu:11371/pks/lookup?op=get&search=0xE38CCEF1>