PUBLIC MARKS with tags smtp & messaging

Stalker Software is the technology leader in messaging and collaboration for a multitude of operating systems. We meet the needs of any size operation, from 10 corporate collaboration and email users to 58 million wireless subscribers. Our flagship product CommuniGate Pro not only supports email and calendaring but is a SIP based server for Instant Messaging, VoIP and video conferencing as well as

A list of 28 (and counting) free and commercial SMTP servers for Microsoft and Linux servers.