At 03:02 AM 3/5/2009 -0800, Ned Freed wrote:
So yes, this may be an example of an SMTP relay violating RFC-5321. The
quote above was from a paragraph in 5321 talking about recipient addresses,
however.
The quote in question is from section "2.3.11 Mailbox and address" and that's
under the SMTP terminology heaing. It is in no way specific to recipient
addresses.
OK, if we interpret the MUST in section 2.3.11 to mean all email addresses,
Given that it's in a general terminology section, I don't see how we have
a choice.
then something should be fixed. The prohibition on SMTP relays changing or
re-interpreting local parts should apply only to recipient addresses.
But that goes much too far. For example, I don't want externai systems forcing
my addresses to lower case (or upper case) on a whim.
I'm with Hector on this - you shouldn't be allowed to modify addresses you
don't own, nno matter where they appear.
Changing a Mail From address should be allowed.
Changing it from one address to another, yes, absolutely. But changing, say,
ned(_dot_)freed(_at_)external(_dot_)com to
Ned(_dot_)Freed(_at_)External(_dot_)Com because you happen to like
mixed case is not OK. Who knows, external.com might just be using
case-sensitive local parts. (The more fool they if they are, not because
software out there diddles witt case a lot - as a rule it doesn't - but rather
because people are pretty sloppy about case when they enter addresses
manually.)
Now, an interesting corner case is something like SRS, where
ned(_dot_)freed(_at_)external(_dot_)com becomes something like
SRS0=P+D=7E=external(_dot_)com=ned(_dot_)freed(_at_)internal(_dot_)com
But this actually isn't dependent on understanding local part semantics in any
way - it only operates on overall address syntax.
I do that so as to redirect any bounces back to my domain where I can deal
with them summarily. I suspend the recipient's account immediately, and
wait until he tells me the problem is fixed. Any other policy could get me
on some blacklist.
Yeah, we are all forced to dance these sorts of dances.
Ned