Caps with sendmail

[Chris P]

I have 1 user that really prefers capital's for his account name.  Only
problem is email to that account does not seem to work.  Does anyone know
if sendmail has issues with capitals?   When anyone emails that account,
my machine replies with "user unknown".  I've tried setting aliases, and
everything I can think of.. Nothing gets through to that account.

Any ideas?  Not a real big deal.. Just would be nice to know.

It was both on FreeBSD 4.8 and 5.0

C.