12. A system for processing an electronic-mail message, the system comprising: memory for storing information regarding a message previously classified as a junk message, the message including a message body; and a message gateway including a summarization and signature generation engine stored in memory, the summarization and signature engine executable by a processor to: summarize the message body of a message received over a communications network to produce a summary, wherein summarizing the message body includes grouping words in the message based on similar meaning, and replacing a group with an identifier that represents the similar meaning, generate a signature based on the summary, compare the generated signature to a database of signatures corresponding to signatures of previously received messages, and processes the message based on at least the generated signature.
12. A system for processing an electronic-mail message, the system comprising: memory for storing information regarding a message previously classified as a junk message, the message including a message body; and a message gateway including a summarization and signature generation engine stored in memory, the summarization and signature engine executable by a processor to: summarize the message body of a message received over a communications network to produce a summary, wherein summarizing the message body includes grouping words in the message based on similar meaning, and replacing a group with an identifier that represents the similar meaning, generate a signature based on the summary, compare the generated signature to a database of signatures corresponding to signatures of previously received messages, and processes the message based on at least the generated signature. 15. The system of claim 12 , wherein the message gateway processes the message by quarantining the message in a junk folder stored at the mail device.