Patent ID: 7769815

Claim:
A method comprising: receiving in a messaging application an electronic message from a sender, the message comprising a message body and a sender address, the message identifying a recipient; identifying the recipient as having a trusted account with a service provider, the account being identified in a trusted database, the account identifying a plurality of sender addresses as being trusted; determining whether the sender address is a trusted sender address by determining if the sender address is identified as trusted in the recipient's trusted account; upon the determination that the sender address is not identified as a trusted sender, identifying the message as potential spam; comparing the message body of the message with a message body of each of a corpus of existing messages in the database that are identified as potential spam; determining if a match exists between the message body of the message and at least one message body of the existing messages; if a match exists, incrementing a message body match counter, the message body match counter tallying a total number of determined matches; comparing the counter's value with a predetermined threshold value, the predetermined threshold value indicating a probability of a message being spam; and identifying the message as spam based on the comparison.