>>> but it isn't hard to make the other databases also understand a +
>>> in them.  or, as i've suggested many times before, @ for hesiod.
>> My reaction is "what if you want + or @ in a username?", [...]
> [...usernames beginning with $...]

> NOTE: In the SMTP RFC, the $ is a legal character to use for an email
> address.

This brings up another story about unusual uses of special characters.

I saw a failure mode in a mailer once that emitted envelope-from
addresses of the form %@the.host.name (where the.host.name is the
machine's fqdn).  This was broken, because the mailer would not do
anything sane if handed that address, but the reason I bring it up is
that at least two sites, on seeing this, bounced the letter, pointing
to the % and saying that it was an illegal entity in the address.  I
read over the RFCs multiple times, trying to find any support for this
claim, with no success whatever.  Neither of the sites' postmasters was
able to produce anything of the sort either; one of them has never
replied to me and the other pointed out that % is commonly used as a
routing character - which I knew - seeming to somehow think that just
because this indicated it may be a bad idea to use a local-part
containing just a %, this somehow justified (a) bouncing the letter and
(b) claiming (incorrectly) that it's illegal.

					der Mouse

			    mouse@collatz.mcrcim.mcgill.edu