[Mailman-Developers] case-sensitive e-mail addresses

Jay R. Ashworth jra@baylink.com
Wed, 2 May 2001 10:19:15 -0400

On Wed, May 02, 2001 at 07:59:20AM -0400, SillyGod wrote:
> Please, could someone advise me if there is still an issue with using
> case-sensitive e-mail addresses with mailman? ie. john.doe@email.com vs.
> John.Doe@email.com would both get delivered? Or would the case-incorrect
> version bounce?

The *right hand side* of a mailbox name (which is what we're actually
talking about here) is case-insensitive because it's a DNS name, and
*DNS*, in turn, is case-insensitive.

The *left hand side* (the "username"), OTOH, must be treated as
case-sensitive, because whether it actually *is*, or not, is
system-dependent... and the "system" in question is the final target
mail server -- in general, I believe that Unix machines are
case-sensitive and Windows ones are not, as is usually the case, but I
don't know Exchange, nor non-Sendmail Unix MTA's, well enough to
guarantee that.

Interestingly, RFC 2822 appears silent on this point, making the
*third* thing this week it's been silent on to my surprise.


-- jra
Jay R. Ashworth                                                jra@baylink.com
Member of the Technical Staff     Baylink
The Suncoast Freenet         The Things I Think
Tampa Bay, Florida        http://baylink.pitas.com             +1 727 804 5015