ELECTRONIC MAIL TRANSMISSION CONTROL PROGRAM, OPERATION METHOD, AND COMPUTER DEVICE

PROBLEM TO BE SOLVED: To provide an electronic mail transmission control program that hardly generates competition with other program, and capable of preventing electronic mail from being erroneously transmitted.SOLUTION: The electronic mail transmission control program includes: a network driver unit N operated in a computer device 1 being the same to that of a mailer M for transmitting the electronic mail, and for seizing the electronic mail tried to be transmitted by the mailer M; a policy determiner P for determining the propriety of transmitting the seized electronic mail; and a proxy server function unit S for determining whether the electronic mail is to be transmitted as it is to an electronic mail server device, in response to a determination result determined by the policy determiner P. An address port number for the electronic mail is brought into a specified port number not used usually in an SMTP, when the electronic mail is determined to be transmitted as it is, by the proxy server function unit S.