Patent ID: 7996475

Claim:
A method for filtering an email between a Simple Mail Transfer Protocol (SMTP) client and server, the method comprising forming at least one set of email parameters from SMTP commands, querying a reputation server before transmitting an SMTP reply code after a MAIL command, receiving a reply, said reply in the form of an IP address whereby some variable information about the email parameters is encoded within the IP address format, and facilitating transmission of the email according to the reply from the reputation server, wherein facilitating transmission comprises bypassing any additional filtering whereby the email is transmitted to a recipient when its email parameters match that of a sender without a history of sending spam; wherein querying a reputation server before transmitting an SMTP reply code after the MAIL command, comprises appending a certain suffix to a string and querying a domain name system wherein a string comprises at least two email parameters concatenated in any order, wherein email parameters comprise at least two of the IP ADDRESS from a connect, the IP ADDRESS from an SMTP packet, HELO command, EHLO command, and the domain name argument of EHLO and domain name argument of HELO.