PostCast Server is an SMTP mail server program that completely replaces your ISP's SMTP server. By making one small change in your e-mail program, you can start sending messages directly from your computer.
The professional edition of PostCast Server has these additional features that are not available in the free version: Support for SMTP gateways Multiple mail folders DNS caching Firewall and proxy support Automatic detection of DNS addresses 50 parallel threads for sending Client-server communication logs
The entry-level SMTP server software. Focuses on direct-delivery of your e-mail messages to your recipient's mailbox and includes a number of useful features.