Emserver is a daemon designed to work with Exim4
to provide greylisting with additional white/black
listing and recipient verification by means of one
simple query from the Exim4 "rcpt to" ACL. It will
reject mail to unknown recipients or blacklisted
senders, accept mail from whitelisted senders, and
temporarily reject (greylist) mail from unknown
senders. It uses memory-tables, so is fast and
uses very little CPU time.
