Patent ID: 9680780
Date: 2017-06-13
CPC Classifications: H04L

Claim:
1. A spam mail identifying method for a mail server, the spam mail identifying method comprising: retrieving a mail header of a mail when receiving the mail; obtaining a plurality of reference servers from a received line of the mail header, wherein each of the reference servers is a mail transfer agent server, and the reference servers transfer the mail according to a sequence; obtaining a plurality of pieces of mail forwarding information of a mail forwarding host and a plurality of pieces of mail receiving information of a mail receiving host of each of the reference servers; comparing the pieces of the mail forwarding information of an i-th reference server with the pieces of the mail receiving information of an (i−1)-th reference server of the reference servers, wherein i is a positive integer; and identifying the mail as a spam mail if the pieces of the mail forwarding information of the i-th reference server are inconsistent from the pieces of the mail receiving information of the (i−1)-th reference server, wherein the step of obtaining the reference servers from the received line of the mail header comprises: analyzing the mail header to find all servers that forward the mail; determining whether a subset exists in the received line, wherein the subset comprises a plurality of specific servers that belong to a same domain among the servers; and adopting one of the specific servers as a reference server that represents the specific servers if the subset exists in the received line.