SMTP recipient validation and/or rejection

["Erik E. Fair" <fair@clock.org>]

Problem: zmailer accepts everything that comes in the SMTP door, only to
validate and send back a notice later that the recipient addresses
specified in the RCPT TO command are invalid (for whatever reason). The
trouble is that so much E-mail has either bogus (bad) or unresponsive MAIL
FROM addresses, that the error replies sit in my outbound queue, consuming
my computing resources and my network connectivity.

Solution: have zmailer validate and reject in the initial SMTP
conversation. This avoids the entire issue.

Question: is it possible to configure zmailer to do this efficiently?

	thanks,

	Erik <fair@clock.org>