This article will cover where you can access the list of IPs as well as point you to a portal where you can test that you have correctly allowed the IPs for delivery
- Access to your Exchange Server and Firewall
- The hostname/external IP of your mail server
You can access the list of IPs here. This site will also allow you to run a test after you have made the changes to your Exchange Server/Firewall.
To run a test enter the hostname/external IP of your mail server under the Firewall section then click submit. This will test every IP that is listed and let you know if there is an issue.