Abstract The Internet has initiated a new generation of communication tools. Internet mail-to-fax, in particular, allows e-mails to be sent to fax machines using simple mail transfer protocol (SMTP). Many such systems have emerged, incurring large collections of mail-to-fax systems throughout the world. Unfortunately, these systems have varying amounts of coverage and system characteristics. Even systems claiming global delivery have unreliable holes in their coverage. As no standard has been set for developing such systems, it inevitably causes confusion to users. In this paper, we review and compare the various system characteristics of the existing Internet mail-to-fax systems. In addition, we propose a unified interface that unifies the existing Internet mail-to-fax systems to help users to use the mail-to-fax service. Other features such as a Web Interface and fax multi-casting are also incorporated to the interface to enhance Internet fax capabilities. The work presented in this paper has provided some important considerations towards the development of a standard for delivering mail-to-fax service over the Internet.