Spammers acquire all the tools used by antispammers to filter email, and they tweak their spam accordingly. Antispam algorithms are acting like predators on the spam ecosystem, culling weak, easy-to-detect spam and leaving behind more virulent, hardier strains.
"There will be an enormous drop in HTML spam, and we will have more text-based and chatty spam," said Graham-Cumming. But "the volume of spam will increase as spammers send variants of messages to get them through."
Although no spammer has yet to fool every Bayesian filter, some tricks work better than others. One recent spam employed a trick that misspelled almost every word in the body, but was still coherent enough to get the gist through.
