On Wed, 7 May 1997 11:31:39 -0400, Eric Thomas <[log in to unmask]>
said:

>         Source routes in RFC821 headers however remain a useful tool
> to date for all sorts of local mail configuration purposes (route
> mail for box X to Y even though the MX record says otherwise because
> of firewall issue Z, etc).  I just can't think of any excuse for not
> accepting them, at a minimum they should be ignored but not rejected.

    There are no RFC 821 headers, just SMTP envelope addresses.


    Based on the principle outlined in section 7.5 of
draft-ietf-drums-smtpupd-04.txt (previously quoted here), we
determined that for operational reasons, we cannot afford to accept
mail that has source routed envelope addresses (at least, not in
the domain part).

    We recognize the value of testing mail via a third party, and
have not turned off support for source-routed addresses in the local
part (i.e., the standard "%" hack), but if it becomes enough of an
operational issue for us, we may be forced to do that as well.


    When the health of the AOL email system as a whole is at
stake, we'll do whatever we have to in order to protect it (and
our customers that depend on it).

    We'll stick to the letter and spirit of the standards as best we
can, but when push comes to shove, we'll fall back on the principle
outlined in section 7.5 of draft-ietf-drums-smtpupd-04.txt, as I
expect any other reasonable person or site would do.


    In fact, it is my opinion that we've been considerably more
lenient for considerably longer than what I consider to be anywhere
close to "reasonable", and now we've been forced to make a larger
correction than would otherwise have been necessary.

    I regret the necessity to make that larger correction, but to
paraphrase statements made to me by Internet email experts more
knowledgable than I:

            RFCs 821, 822, and 1123 specify how email should be
        done in a Perfect World by the Angels, for the Angels, and
        of the Angels.

            However, this is 1997 -- there are no more Angels
        left, and this is about the most imperfect world as could
        possibly exist.

            Now, we are forced to be realistic.



    When the national and international laws have been sufficiently
tightened, as well as the Internet mail protocol itself, maybe we'll
be able to relax restrictions of this sort.  However, I don't see
that happening any time soon, if ever.

--
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>