How does Irides filter for spam?
Irides uses several tools to detect spam. We start by utilizing several Relay Block Lists (RBL’s). These are lists of IP addresses and hosts that are known to be “open”, meaning anyone can send email through them, or spammer friendly, meaning they allow spamming or are owned and operated by spammers. If the message is coming from an RBL listed IP address or host it is rejected. Messages are then run through an heuristic analyzer to be graded on 100’s of different tests that check for tell-tale signs of spam. If the message gets a grade above a certain level, it is consider spam and marked as such. Lastly we do a content scan of the message headers and message body for key words and addresses. Any message containing a key word is rejected.
