E-mail address forced to lower case in user ID?!?

[Claus Assmann]

On Sun, Feb 28, 1999, Nathan Kennedy wrote:

> Last I checked, login names are CaSe sEnsiTive in *NIX, just like anything
> else in UNIX or C.  I've never done it (I always use lower case for login

Some UNIX systems disallow upper case characters in the username
(Sun OS 4 man page says so...)

> names, and that is accepted practice with UNIX), but you could have one
> user named Joe and another named joe.  Now-- I telnetted and tried it, and
> it seems that some (all recent?) sendmails will kludge the capitalization,

It's an option in sendmail (as nearly everything) (F=u for the mailer
makes the name case-sensitive). If you use procmail for delivery, it
will usually force the name to lowercase. So your best bet is
not to use upper case characters (some older termcap entries even assumed
that the terminal has only upper case characters when you login and type
an upper case character first!).

Proposal: make this a compile- (or even run-) time option.