To discriminate whether the incoming mail is from an actual sender or a junk mail by checking.

A header information analyzer 202 analyzes the header information 214 obtained by a header information acquiring section 201 and finds out an incoming/outgoing mail history and mail information to be analized. A delete requesting section 210 consisting of an inquiry section 211 and a message preparing section 212 prompts a personal computer 103 to use this system, and requests a mail server 101 to delete the junk mail while sending a message to the junk mail sender.