Here's one battle I want to watch from very far away.
ezmlm and some other list packages that use qmail as their MTA send all posts
and digests out with a VERP that includes -recipient=domain.of.recipient and
confirmation requests for joining and quitting with reply addresses that
likewise include equal signs.
It has just come to light today that webmail accounts on sites that run
BigMailBox will not accept equal signs in outgoing addresses, considering
them illegal. So users of such systems cannot confirm their attempts to
join such a list, or, if they got on some other way, they cannot confirm
their attempts to leave it. Also, I'd guess that list distributions to
closed, renamed, or over-quota accounts on such sites aren't bounced back,
because the mailer-daemon probably can't write to an address with an equal
BMB software is free to webmasters in return for carrying ads on their sites
for advertisers who buy space from BMB, and the sites themselves get a cut of
the advertising revenue. At least two of my webmail accounts run BMB.
(BMB does allow hyphens, periods, plus signs, ampersands, apostrophes, pipes,
and underscores. What the sense is in allowing ampersands and pipes, I can't
guess; there is a risk that it may be given unquoted to a shell prompt or
shell script at the other end. Meanwhile, if ever I have to send a suffixed
Reply-To: address to what could be a BigMailBox site, I suppose a pipe or an
ampersand could substitute for the usual equal sign.)
Somebody is wrong here. and I've a feeling it isn't the qmail people.