One of the useful feature of Alligate server is Message Blocking. If you wish to use this feature then refer the below steps:

1. Open the "Alligate SMTP Gateway Control Panel". (Start -> All Programs -> Alligate)

2. From the selection menu click on “Blocking” option and set the settings as per your requirement.

I have attached screen capture of the same which will guide you how it looks.

Attached Files