First, configure the IP-based policy for connections from internal SMTP clients.
- Go to Policy > IP Policy > IP Policy and click New.
- Click Enable.
- Set Source to the IP address and netmask of your subscriber network.
- Under Profile, select the internal_session_profile from the Session drop-down list.
- Click Create.
Configure the IP-based policy for connections from external SMTP clients.
- Go to Policy > IP Policy > IP Policy. Select the default policy whose Source and Destination are both 0.0.0.0/0 and click Edit.
- Under Profiles, select the external_session_profile from the Session drop-down menu.
- Click OK.