RFC2822 doesn't explicitly say. What it does say:
addr-spec = local-part "@" domain
The local-part portion is a domain dependent string. In addresses,
it is simply interpreted on the particular host as a name of a
The local-part could be case sensitive if the mail server so desires.
As far as I know, none of the major mail services use case sensitive
names. A some years ago, I did run across a few small organizations
that were using Unix based systems with case sensitive mail boxes. I
suspect that they were using the built-in Unix mail commands without a
regular mail server.
The domain portion of the name is never case sensitive because Internet
domain names never are.
RFC2821 does say:
Any system that includes an SMTP server supporting mail relaying or
delivery MUST support the reserved mailbox "postmaster" as a case-
insensitive local name.
That again implies that other local names could be case sensitive.
Mike - http://pages.prodigy.net/michael_santovec/techhelp.htm
"N. Miller" <anonymous@xxxxxx> wrote in message
> On Thu, 26 Jun 2008 19:46:19 -0500, robertmiles@xxxxxx
>> Many require you to be careful about which
>> letters in your password are CAPITAL and which are lowercase.
> For some values of "many". I can't find a requirement, in RFC 2822,
> for case
> sensitivity in email names. I suspect that any email server which
> case sensitivity is not in compliance with RFC 2822. Which is not a
> Thing"® on the Internet.
> ~Oh Lord, why have you come
> ~To Konnyu, with the Lion and the Drum