How to check for existing mail accounts?

[René Berber]

Johnny Stork wrote:

> its sendmail

You don't need a milter (but you can choose to), you can use the 3rd 
party FEATURE(`local_sender_check') :

   http://ultra.ap.krakow.pl/~raj/sendmail/english.html

I've been using it for 2 years with no problems.  Of course this is for 
local users, if you have users defined in LDAP or something similar, 
then something else has to be used.
-- 
René Berber