Facsimile mail system linked to data communication system

A linked mail/message board system wherein a data communication center (10a) and a facsimile mail center (20a) are linked. The control data of facsimile mails/message boards are held in a data communication center, as well as in the facsimile mail center. The data communication center has a unit for receiving from one of data terminals connected thereto, a command for operating the facsimile mail center, and a unit for transferring the command to the facsimile mail center. The facsimile mail center has a unit for receiving the transferred command, and a unit for executing the command. The data communication center has a unit for receiving from one of the data terminals and transferring to the facsimile mail center, additional information to be attached to a facsimile mail when the facsimile mail is delivered. The data communication center has a unit for transferring an electronic mail to the facsimile mail center, and the facsimile mail center has a unit for converting the additional information and the information in the electronic mail into image data to transmit the image data by facsimile.