An email transmission apparatus operates to reduce mis-transmission of an email even if a mistake occurs in the check of a destination address. The email transmission apparatus for transmitting a mail to an address designated as a destination includes a counter for counting return mails which were returned with the designated address as a source in response to transmitted mails. The email transmission apparatus further includes a judging function to obtain, from the counter, a receipt frequency of the return mail with a designated address of a mail to be newly transmitted as a source, and to then judges whether the designated address is an address which may cause mis-transmission on the basis of the receipt frequency. Also provided is a notification function that is responsive to the designated address being judged to be an address which may cause mis-transmission. The counter includes a receipt frequency information database for recording a receipt frequency of the past return mails. The judging function determines that the designated address is an address which may cause mis-transmission when the receipt frequency of the return mails is lower than a predetermined threshold value.