15. A non-transitory machine-readable storage medium including instructions executable by one or more processors to determine a probability that an email message is spam, the non-transitory machine-readable storage medium comprising: instructions to receive an email message; instruction to identify one or more words and/or phrases of the email message that are likely being obfuscated; and instructions to determine a probability that the email message is spam in dependence on at least both of the following which particular one or more words and/or phrases are identified as likely being obfuscated, wherein identifying some particular words and/or phrases as likely being obfuscated increases the probability that the email message is spam more than identifying other particular words and/or phrases as likely being obfuscated, and which particular one or more obfuscation techniques are being used to obfuscate the one or more words and/or phrases that are identified as likely being obfuscated, wherein detecting use of some obfuscation techniques increases the probability that the email message is spam more than detecting use of other obfuscation techniques.
15. A non-transitory machine-readable storage medium including instructions executable by one or more processors to determine a probability that an email message is spam, the non-transitory machine-readable storage medium comprising: instructions to receive an email message; instruction to identify one or more words and/or phrases of the email message that are likely being obfuscated; and instructions to determine a probability that the email message is spam in dependence on at least both of the following which particular one or more words and/or phrases are identified as likely being obfuscated, wherein identifying some particular words and/or phrases as likely being obfuscated increases the probability that the email message is spam more than identifying other particular words and/or phrases as likely being obfuscated, and which particular one or more obfuscation techniques are being used to obfuscate the one or more words and/or phrases that are identified as likely being obfuscated, wherein detecting use of some obfuscation techniques increases the probability that the email message is spam more than detecting use of other obfuscation techniques. 19. The non-transitory machine-readable storage medium of claim 15 , wherein the instructions also include: instructions to deobfuscate each word or phrase of the text that is identified as likely being obfuscated, to produce deobfuscated text; and instructions to compare the deobfuscated text to text of one or more other messages known to not be spam; wherein the determining the probability that the email message is spam is also in dependence on results of the comparison of the deobfuscated text to text of one or more other messages known to not be spam; wherein the more similar the deobfuscated text is to the text of at least one of the one or more other messages known to not be spam the lower the probability the email message is spam.