Add domain and IP to whitelist

Add domain and IP to whitelist

You create an IP Allow list or IP Block list by editing the connection filter policy in the Exchange admin center (EAC). The connection filter policy settings are applied to inbound messages only.

1. In the Exchange admin center (EAC) (https://outlook.office.com/ecp/) navigate to Protection > Connection filter, and then double-click the default policy.
2. Click the Connection filtering menu item and then create the lists you want: an IP Allow list, an IP Block list, or both.

To create these lists, click Add Icon. In the subsequent dialog box, specify the IP address or address range, and then click ok. Repeat this process to add additional addresses. (You can also edit or remove IP addresses after they have been added.)

3. Optionally, select the Enable safe list check box to prevent missing email from certain well-known senders. How? Microsoft subscribes to third-party sources of trusted senders. Using this safe list means that these trusted senders aren’t mistakenly marked as spam. We recommend selecting this option because it should reduce the number of false positives (good mail that’s classified as spam) you receive.
4. Click save. A summary of your default policy settings appears in the right pane.

Please refer the below link for more details.

Configure the connection filter policy

To add a domain to whitelist.

1. In the Exchange admin center (EAC) (https://outlook.office.com/ecp/) navigate to Protection > Spam filter, and then double-click the default policy.
2. On the Allow Lists page, you can specify entries, such as senders or domains, that will always be delivered to the inbox. Email from these entries is not processed by the spam filter.

1. Add trusted senders to the Sender allow list. Click Add (+), and then in the selection dialog box, add the sender addresses you wish to allow. You can separate multiple entries using a semi-colon or a new line. Click ok to return to the Allow Lists page.

2. Add trusted domains to the Domain allow list. Click Add (+), and then in the selection dialog box, add the domains you wish to allow. You can separate multiple entries using a semi-colon or a new line. Click ok to return to the Allow Lists page.

Please refer the below link for more details.

Configure your spam filter policies