Simple greylisting daemon for use with Exim & other MTAs
This daemon provides a simple greylisting implementation for use with Exim and other mail transport agents (MTAs). For an
introduction to greylisting, please refer to Evan Harris' whitepaper at:
In essense, greylisting is a simple but highly effective means to weed out messages that are being delivered via spamware/
ratware tools. The idea is to establish whether a prior relationship exists between the sender and the receiver of a message.
Most of the time it does, and the delivery proceeds normally.
On the other hand, if no prior relationship exists, the delivery is temporariliy rejected (using a 451 SMTP response).
Legitimate MTAs will treat this response accordingly, and retry the delivery in a little while. In contrast, ratware will often
try to hammer on your server repeatedly within a short period of time (i.e. seconds), and/or simply give up and move on to the
next target in its address list.
The package contains a sample configuration snippet for use with Exim 4.
Tor Slettnes <email@example.com>