On Mon, Sep 10, 2007 at 09:26:36PM -0700, Timothy J. Miller wrote:
2822 says that the domain-part of an address is interpreted as a domain
name, and the DNS RFCs say domain names are case-insensitive. But it looks
to me like 2822 is silent on *local-part* case sensitivity.
RFC 2822, section 3.4.1:
"The local-part portion is a domain dependent string."
My interpretation of that is "Don't touch it. At all. It's not yours."
Logic can take us either way; i.e., since RFCs are generally silent unless
insensitivity is needed, local-part must be sensitive--or, alternately,
since the RFC is silent in this case it's best to interpret for maximum
compatibility, so local-part must be insensitive.
And most MTAs and MUAs in my experience treat local-part as case
insensitive.
Probably not a good assumption in general, at least for MTAs:
RFC 2821, section 2.4:
"The local-part of a mailbox MUST BE treated as case sensitive. Therefore,
SMTP implementations MUST take care to preserve the case of mailbox
local-parts."
Should the local-part of an RFC2822 addr-spec be interpreted as
case-insensitive?
I think "no", based on the citations above. I do empathize with you about the
particular problem you have. I've seen agents change
Blake(_dot_)Ramsdell(_at_)example(_dot_)com to
BLAKE(_dot_)RAMSDELL(_at_)EXAMPLE(_dot_)COM on more than one
occasion.
Blake
--
Blake Ramsdell | Sendmail, Inc. | http://www.sendmail.com