Enable Split Domain Routing
Login to the Customer Portal as an admin.
- Click on the Exchange 2010 tab at the top.
- Click on Settings from the sub-menu.
- Click on Routing from the menu on the left.
- Click the check box to enable Split Domain Routing
- Enter your email server address, port and number of users being routed.
Click Save when finished.
If your firewall is limiting SMTP connections, then please allow connections from 188.8.131.52/24