🚀 go-pugleaf

In article <9742@swan.ulowell.edu>, page@swan.ulowell.edu (Bob Page) writes:
> I'm getting uucp mail from some hosts with From_ lines that have
> route-addrs in them.

I've seen such horrors arriving here, too.  Mit-eddie seems to be the
worst of our immediate links for handing us such things, for what
that's worth.  (I've even seen host%host!user, which I was told was due
to a bug in smail that would be fixed Real Soon Now.  Bug or not, it's
been showing up with great regularity, and hadn't been fixed sometime
Saturday morning, when I got the most recent such.)

I eventually got fed up with nonsense like this in reply addresses and
put a patch into rmail so that it understand the header to a limited
extent.  It checks for From:, To:, Cc:, and From_ lines, and if it
finds any, it checks the addresses on them for sanity.  If it finds
anything dubious it inserts a warning at the top of the body of the
message before passing it to sendmail.  (Unless the mangled address is
the envelope to-line, in which case it gets sent to postmaster (me)
instead, because the probability of its reaching its intended
destination is quite low.)

How do I tell dubious addresses?  They're addresses which mix ! with
either % or @.  Initially, it was just mixed ! and %, until I saw some
horrors that came from mixed ! and @ that were technically legal RFC822
but required interpretations different from those prescribed by the RFC
if they were to work.

This seems to be an acceptable compromise.  All mail leaving via UUCP
gets completely rewritten to bang paths (least common denominator).
Dubious mail probably carries damaged addresses, but it also carries a
warning which makes the recipient aware of this; the warning quotes the
line seen by rmail when it hit this machine.  I got a few complaints
that I should be sending the grumble to the postmaster on the next-hop
machine, but (a) that's not necessarily the guilty machine and (b) I
don't really care whether they fix their mailer or not.  (The
*recipient* of the letter might care, though....)

> Bob Page, U of Lowell CS Dept.  page@swan.ulowell.edu  ulowell!page
> Have five nice days.

That's a curious balance between stated meaning and implied meaning.
I like it.

					der Mouse

			old: mcgill-vision!mouse
			new: mouse@larry.mcrcim.mcgill.edu