A communication apparatus that reduces the number of procedural steps that need to be performed by a user in attaching facsimile data to an e-mail and transmitting the e-mail, includes a CPU of a personal computer that starts a transmission program for performing a series of operations, such as causing a facsimile apparatus to scan a document, generating an image file of the scan data, attaching the image file to an email, and transmitting the e-mail. In accordance with the transmission program, a mail address, a scan mode, and a format for generating an image file of the scan data are set. Then, the CPU instructs the facsimile apparatus to start scanning a document. The CPU receives and stores scan data. Upon receiving a scan end command, the CPU converts the scan data into the format designated as described above, and generates an image file of the scan data. After attaching the image file to an e-mail, the CPU transmits the e-mail.