exim.conf.local

# Excerpt from the exim.conf file (for greylisting):
#
# ACL used after the RCPT command
check_recipient:
  # Start with blacklists, DNS blacklists and other deterministic means of
  # blocking email
  #
  # Also include whitelisted senders and/or recipients that we want to ALWAYS 
  # accept mail from.
  #
  
  # Then test for greylisting for domains we accept (or relay)
  defer   message = Temporarily unable to process your email. Please try again later.
          #skip if authenticated (with SMTP AUTH ...)
          !authenticated = *
          # Greylisting is considered only for domains we accept:
          domains = +local_domains : +relay_domains
          condition = ${readsocket{/ramdisk/var/spool/exim/greylistd.sock}\
                       {IS_DEFERRED $sender_host_address $sender_address $local_part@$domain\n}\
                       {5s}{}}
          log_message = $sender_host_address $sender_address $local_part@$domain greylisted

  # Then other checks performed when the RCPT TO: command is received