How to whitelist or blocklist an IP Address using Office 365

Here's a simple procedure to whitelist or blocklist an IP Address using Office 365 Exchange Admin Center (AEC).
Note: You need to have an admin account to update your Office 365 setting using AEC.

1. Login to Office 365 website (http://sqit.com/ms) short URL to https://portal.microsoftonline.com website.
2. Click on Admin, then Exchange.
3. In Exchange Admin Center (AEC), click on protection, then connection filter.
4. Double click Default, click on connection filtering to will see your existing Allowed IP Address and Blocked IP Address.
5. In Allowed IP Address, click the (+) to add your external IP Address. See the captured image as an example. I removed (blue covered) our external IP address for safety.
6. Put check on Enable safe list, the click on save.

Then you wait for the Microsoft servers to sync.

Alternative approach using the following.

• In Office 365 admin center, click on support link to submit a service ticket to Microsoft customer support.
• or Send email to delist[@]messaging.microsoft.com with your external IP Address to whitelist.

Cheers.