6.1.9 Les messages encodés en HTML sont des Spams
Many spammers encode the contents of their messages with base-64 so that filters cannot see the incriminating words they contain. SpamSieve can decode and look inside these messages. This option causes it to mark all such as spam, regardless of their contents, on the theory that legitimate senders do not try to obscure their messages. This does not affect messages encrypted with PGP.