There's another subtlety here - lists that filter mail from
non-subscribers penalize folks who use subaddressing for incoming
list mail, since they don't post from the same address at which they
are subscribed. Ideally, lists should not consider subaddresses
when comparing a contributor's address against the list of
subscribers. Failing that, it's helpful if a subscriber can get his
"From" address registered as one for which there is special
permission to post.
Your suggestion to "not consider subaddresses" is impractical at best,
and illegal regardless.
On the contrary, it's clearly practical as I have running code in
bulk_mailer that does this (which will be in the next release).
Nor is it illegal. Since there are no standards regarding list filtering,
there are no standards that prohibit lists from doing filtering using
fuzzy matching rather than exact matching on an address. My guess is that
most lists that filter on source address are already taking liberties
when comparing addresses - they're doing case-insensitive comparisons
of the local-part when according to the standards the local-part is
allowed to be case-sensitive.
It doesn't take rocket science for the list to seperately compare
the domain of an email address and the portions of the local-parts
up to but not including any of the separators commonly used:
( + - / . = # )
hosting the elist. Even if it did you're suggesting the elist server
should peek or otherwise parse the localpart of an non-local email
address and that is wrong.
Guess we'd better put a stop to those case-insensitive comparisons, then.
The only practical solution is, as you propose, that the elist needs to
have a separate list of addresses approved to submit messages.
Actually I've demonstrated that there is another practical solution, one
which is unlikely to penalize those using subaddresses at all.
Keith