UltraSMTP is operated by the same people at Meixler Technologies who ran the widely-used GreenFax internet faxing service - offering fax-to-email, email-to-fax, and web-fax services from 1998 until 2017. In 2017, GreenFax was acquired by j2 Global, Inc (NASDAQ:JCOM), parent company of eFax.com. In our experience over the years in operating GreenFax, we saw first-hand how email has become increasingly less reliable. At the same time, we grew increasingly frustrated by the lack of transparency that most SMTP services provide to their end users - making it almost impossible to know what happens to sent messages after leaving the outbox. As a result, we set out to build a mail server to mitigate the problems of email unreliability, and provide end users with tools to track and confirm delivery of sent messages. UltraSMTP is the result of our efforts. We began work on UltraSMTP in the late 2000's, and used it in-house for a number of years until offering the service to the public in 2010. The service is now used by a rapidly growing base of users around the world.