We reference it on our FAQ page.

http://www.lsoft.com/manuals/lsv-faq.stm#5.19

RFC821 is clear that left side is case-sensitive while right side is
case-insensitive.

Section 2, THE SMTP MODEL

(...)
    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.
(...)

RFC1035 reinforces the right side case-insensitivity issue.

2.3.1. Preferred name syntax

(...)
Note that while upper and lower case letters are allowed in domain names,
no significance is attached to the case. That is, two names with the same
spelling but different case are to be treated as if identical.
(...)

Nathan

At 23:26 2002/09/28 -0400, Glenn Darwin wrote:
>Here is Lsoft support's reply to my problem with dupes during the bulk add...
>
>What I have done is downloaded all the subscribers and used ultraedit to
>tranform all caps to lower case.  Then I did a bulk add with the option to
>delete all and reload....
>
>Before the load I had 15,142 subscribers.  And a ton of complaints about dupe
>subscriptions....  After the load I ended up with 14,097.  After letting
>Listserv weed out the dupes in the same format...
>
>I would like to see the RFC to back up Lsofts claim that every thing on
>the left
>of the @ sign is not case dependant.
>
> From now on when I do a 1000 plus load I'm going to transform every thing to
>lowercase to keep this from happening again.
>
>Glenn
>http://www.corvettemuseum.com
>
>Clara Lyon wrote:
> >
> > > Is there any way to stop duplicate e-mail addresses to be added in
> 1.8d...  When
> > > using the bulk add I get no indication of duplicates. I get a notice
> when using
> > > the e-mail interface.  I'm spending a lot of time taking care of
> complaints of 2
> > > or more copies of post going out, which is a result of duplicate
> e-mail address
> > > with one or more characters being a different case.
> > >
> > > Has this been addressed in 1.8e?
> >
> > Not in the case your speaking of.
> >
> > Joe@domainname
> > would be an entirely different address than
> > [log in to unmask]
> >
> > Anything left of the @ sign is case sensitive, anything left of the @ is
> > not
> > >
> > > Glenn
> > > National Corvette Museum
> > > http://listserv.corvettemuseum.com
> >
> > --
> >
> > Regards,
> >
> > Clare Lyon
> >
> > Support is available 9:00-18:00 ET, Monday-Friday
> > Except for the following Holidays:
> > Http://www.lsoft.com/products/default.asp?items=holidays
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