New submitter hmilz writes "I've been using procmail for years to filter my incoming mail, and over time a long list of spam patterns was created. The good thing about the patterns is, there are practically no false positives, and practically no false negatives, i.e. I see each new spam exactly once, and lose no legit mail. This works by using an external spam-patterns file, containing one pattern per line, and running an 'egrep -F' against it. As simple as this is, with a long pattern list this becomes rather slow and CPU consuming. An average mail currently needs about 15 seconds to be grepped. In other words, this has become quite clumsy over time, and I would like to replace it by a more (CPU, hence energy) efficient method. I was thinking about a small indexed database or something. What would you recommend and use if you were me? Is sqlite something to look at?"