eWall has two versions:X Edition is cheaper but only for a limited number of low-cost or free mail servers such as XMail, hMailServer, MailEnable, ArGoSoft Mail Server and they are named "X" based on the word Xmail, while Unlimited Edition is unrestricted.
Anti-spam solution for email server with eWall Picture 1
Anti-spam solution for email server with eWall Picture 2
General SMTP session:
The image below shows the general SMTP Session, the appearance of eWall events and some security features.
Anti-spam solution for email server with eWall Picture 3