Hexamail Guard Administration Guide - Initial Setup Wizard - Mail Server
Hexamail Guard neesd to send email to your existing email server for delivery to your users. Choose the mail server you have on this page
If you are running Exchange and Hexamail Guard on the same machine use this setting to automatically have Exchange settings modified ready to run with Hexamail Guard.
Your existing Exchange settings will be recorded and restored if you uninstall Hexamail Guard. The settings changed are: Protocols/SMTP/Default SMTP server/Bindings, Protocols/SMTP/Default SMTP server/Delivery/Smarthost