Ned Freed writes:
But that's the problem - this is not what RFC 5321 says.
It's not what 3501 says either ;) More of a one-sentence simplification
than a full and exact description.
SMTP server do stuff like expand lists all the time. For those tests
to be done competently some amount of interpretation of local parts
may be needed, such as ignoring the possibility that the local part
is case sensitive.
Oh, this makes sense. I wasn't aware of that. I ran into the same issue
whem implementing "group reply" in a MUA, but hadn't realised that MTAs
could run into that.
While there may not be any conflict between RFC 3501 and RFC 5321
since they deal with separate components, the fact remains that
there's a conflict between what real world implementations do and
what RFC 5321 says must not be done.
I agree with that. Email-arch, however, deals with both, and attempts to
describe the running code too, so IMO it can't just cite 5321. That
would be overly simplistic.