If you are using Exchange Server 2010, Exchange Server 2013, Exchange Server 2016, or Exchange Server 2019, you can set up an IP allow list using the command line. 

See these instructions for more information.

If you do not wish to use the command line, follow the instructions below to set up an IP allow list using the exchange GUI.

1. Log into your mail server admin portal and click Admin.
2. Click on Exchange.
3. Click on connection filter (beneath protection heading).

• Click on connection filter in the protection section, then click the
• Click on connection filtering.
• Under the IP Allow list, click the  to add an IP address.
• On the Add allowed IP address prompt, add our IP addresses one at a time.
• Click  Save. After setting up an IP allow list, you will want to set up a mail flow rule to permit our mail to bypass spam filtering and the clutter folder.