Re: [Jmap] Address Validation (was Re: Submission)

["John Levine" <[e-mail]>]

In article <[e-mail]> you write:
>Do we want JMAP-Mail to include a facility to check whether an address would be accepted for mail delivery by the server - presumably the result is a
>tristate of [definite YES, Unknown, definite NO] via whatever response method is used.

I'm trying to think of a plausible use case for separate checks rather
than at submission time, and also trying to think of a plausible way
to do useful checks on non-local addresses.

The use cases I think of are pretty contrived, like someone just
uploaded an address book and wants to prune out the bogus addresses.

For the latter, since nobody supports VRFY and EXPN any more (for good
reasons,) and RCPT TO probes tend to get you blacklisted, the answer
for remote addreses is always going to be "maybe" unless you mistype
a nonexistent domain.

So I wouldn't bother.  The addresses will get checked when people send
the message, just like now.

R's,
John