As people have pointed out, some of the commercial MLMs do Message-ID and
checksum storage to prevent these problems. Someone mentioned Listproc,
but from their message it sounds like they meant the old 6.0c version.
The commercial version, 7.X, correctly stores the checksums of the body
of the message, stripping the headers, exactly as suggested. I'm pretty
certain that that would have elegantly prevented your situation.
>That one double quote had other serious consequences too. I approved one
>copy of the message, which went out with the line
>`To: Ecolog!a Theor"tica <theoretical-ecology@...>'
>in it, and it seems that almost half of the subscriber sites bounced it
>because of the unbalanced double quote.
That's right. That's not a legal RFC822 To: line. Ideally, your mail
system should have bounced it too. I think the correct line would have
To: "Ecolog!a Theor\"tica" <...>
(but I'm not completely certain about the backslash to escape the quote...)
>Since there are several hundred
>subscribers, this meant a lot of bounce messages. I don't know much
>about mail headers, but what if someone submitted a perfectly legitimate
>message with a Subject line like
>`Subject: Applications of x" = -kx to ecological systems'
>where x" is standard math for second derivative. Would that bounce too?
Nope. The Subject line is not processed by an SMTP MTA.
>In general, none of our lists are moderated, so does anyone
>have any ideas on how to avoid this in the future? By the way, this is a
>Majordomo list, but it seems to me that it could happen to any list.
Well, I'd continue to urge people who need more control or more performance
than what SmartList or MajorDomo provide to consider purchasing Listproc.
I was pretty happy with it when I had the opportunity to use it, and have
been fairly unhappy with the inflexibility of Majordomo (which I run now,
at a different site). But we're running less than 10 lists (rather than
200) with something like 1000 times fewer recipients, so it's not worth
the money to us...
Harlan Harris Missive/AIX
Wingra Technologies, Inc. The Simple Solution to Email Integration
+1 608 238 4454 +1 608 238 8986 (fax)