sendmail or cyrus question... not sure

[Chris Mattingly]

Hi all,

Please send me over to a sendmail list if this question would be better 
suited over there, but I'm hoping to get some help here. :)

I'm using sendmail 8.13.1 & cyrus 2.2.12.  In my sendmail config, I have 
set cyrusv2 as my LOCAL_MAILER.  What's happening is that mail for any 
recipient is being accepted by the MTA, failing the lmtp delivery as a 
non-existent user, then bouncing back to me (postmaster).

What's the cleanest way around this problem?  Obviously, the solution 
I'd like is for invalid recipients to get blocked at the "RCPT TO" command.

Thanks!
-Chris