1. A method, comprising: scanning, in response to a determination that a first time period has ended, email messages from an email address of a sender previously identified as a source of spam; placing the email address of the sender in a clean list such that scanning software is subsequently prevented from performing a full scan of additional messages from the email address of the sender, the placing performed in response to a determination that a count of the email messages that are clean has exceeded a threshold over a second time period, the second time period similar or less than the first time period; and placing the email address of the sender in a spammers list in response to a determination that a count of the email messages that are spam has exceeded a threshold over a third time period greater than the second time period, wherein the spammers list is replicated to another server.