Abstract: This invention relates to a method and system for allowing electronic mail (“e-mail”) users to control the acceptance and transmission of electronically mailed messages over a communications network such as the Internet by permitting the intended recipient (and/or at system administrator) to define what is authorized (i.e., acceptable). An e-mail processor constructed in accordance with the invention substantially eliminates communication of unauthorized e-mail to an intended recipient by permitting a definition of the characteristics of authorized e-mail. E-mail failing to include one or more such characteristic is rejected. Accordingly, the process includes means for reading selected data strings of e-mail, means for comparing the stored and read data strings to identify a match, and means for rejecting the e-mail if no match is found.