> >>So. RFC 3501 (page 50-51), says that the localpart of a From: address is > >>matched case-insensitively when IMAP servers process SEARCH or UID > >>SEARCH commands. RFC 5321 says that SMTP servers process localparts > >>case-sensitively. Both rules go back essentially unchanged to very old > >>RFCs. > > > >But that's the problem - this is not what RFC 5321 says. It says: > > > > Consequently, and due to a > > long history of problems when intermediate hosts have attempted to > > optimize transport by modifying them, the local-part MUST be > > interpreted and assigned semantics only by the host specified in the > > domain part of the address. > > > >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.
> A mailing list is a mediator (at the User level), not a relay at the SMTP > level. THen what about autoforwarders with access controls? > It *is* the "host specified in the domain part of the address". So it should > interpret the local part. Of the recipient address, sure. But not the originator address. > When I send this message to [email protected], only imc.org knows how to > interpret the local part. RFC 5321 is not in conflict with reality, at least > in this example. When you send mail to [email protected], a check is made to see if you're a subscriber to the list. I doubt that your address is in imc.org and that check is probably done in a case-insensitive way. Replace [email protected] with an autoforwarder with access control, and now RFC 5321 *is* in conflict with reality. Ned
