Allow only authorized SMTP servers to communicate with your mail server
Last Updated: 10/3/2017 5053 Views 6 Users found this article helpful

This article describes how to block all traffic from the WAN to an SMTP Server on the LAN or DMZ, except a range of IP Addresses on the WAN. This requirement usually arises when the user has a managed or hosted Spam Filtering service (eg. Postini) on the WAN and wishes to lock-down his incoming email to that service.


Creating an Address Object for the IP Addresses of the hosted service:

Login to the SonicWall Management interface.
Navigate to Network | Address Objects.
Create a new Address Object with following values:
Name: Postini Network
Zone: WAN
Type: Network (This could be changed to Range or Host as required)

See the full Tech Document here: