A set of unsolicited e-mail messages is collected and “finger printed” by either sampling the unsolicited message and using portions of the samples to form the identifier or by hashing a portion of the message. These “finger prints” are used to construct an unsolicited message database. The client's...http://www.google.es/patents/US7310660?utm_source=gb-gplus-sharePatente US7310660 - Method for removing unsolicited e-mail messages
