AndrewSchaefer writes: "Every few years I rebuild my Linux server and one of the things that I've never been happy with is spam filtering. Three years ago I used a combination of Amavis and SpamAssassin but found that a lot of spam continued to trickle through. One of the key features I'd like to take advantage of would be some of the online blacklist and confirmed spam databases. While spam is a problem I don't want to have to dedicate a lot of time to tweaking rules or downloading new rulesets to defeat new techniques. The other thing I'd like to try to get right is the user interface for administering mail filtering. I host several friends' email inboxes as well and don't want to have to deal with sorting through false positives for them. My ideal setup would include a way for individual users to flag messages as spam, view the messages tagged as spam, and whitelist senders without having to SSH in and run a script."