On Wed, 11 Jan 2006 07:43:56 CST, Steve Price said:
> I just got word that someone is blocking messages from a LISTSERV I
> help manage because the domain name is all caps in the from address.
> I realize the problem is really on their end.  However I wondered
> about the history of capitalizing the domain name and perhaps if
> there was a knob that I'm not aware of to turn it off.

I'm tempted to tell them to go stick it in a pig.  If they insist on running
their mail server in an incompetent manner, their users should feel the pain. ;)

RFC821, section 2, August 1982:

   Commands and replies are not case sensitive.  That is, a command or
   reply word may be upper case, lower case, or any mixture of upper and
   lower case.  Note that this is not true of mailbox user names.  For
   some hosts the user name is case sensitive, and SMTP implementations
   must take case to preserve the case of user names as they appear in
   mailbox arguments.  Host names are not case sensitive.
                       ----------------------------------

RFC2821, section 2.4, April 2001:

   Verbs and argument values (e.g., "TO:" or "to:" in the RCPT command
   and extension name keywords) are not case sensitive, with the sole
   exception in this specification of a mailbox local-part (SMTP
   Extensions may explicitly specify case-sensitive elements).  That is,
   a command verb, an argument value other than a mailbox local-part,
   and free form text MAY be encoded in upper case, lower case, or any
   mixture of upper and lower case with no impact on its meaning.  This
   is NOT true of a mailbox local-part.  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.  Mailbox
                                                                -------
   domains are not case sensitive.  In particular, for some hosts the
   ------------------------------
   user "smith" is different from the user "Smith".  However, exploiting
   the case sensitivity of mailbox local-parts impedes interoperability
   and is discouraged.

I don't know how to make it any more clear that they're being idiots.

There almost certainly isn't a knob to change it, because it shouldn't
need changing.

You might check your Listserv configuration, and see if you have the NODE=
specified as upper case - if it is, using lower case instead may help.