A data communication apparatus which does not have a function for receiving, via a mail server, e-mail sent by an external device includes a setting unit configured to set a POP account for the mail server, a reading unit configured to read a document to generate image data, a sending unit configured to send the generated image data as an e-mail via the mail server after performing authentication based on the POP account set by the setting unit, and a notification unit configured to transmit to the mail server, a delete instruction to delete an e-mail stored in a mailbox on the mail server.