Steps to whitelist an email address or a domain
Microsoft Office provides a layer of protection for your email account which diverts suspected spam emails to a separate folder away from the Inbox.
But it is always a possibility that you want some of those emails to come to the Inbox.
To bypass SPAM filtering, such emails and domains can be whitelisted.
Here are the steps to whitelist an email address or a domain.
Log in to Microsoft 365 Exchange Admin center, you can visit the admin center from: https://outlook.office365.com/ecp/
Sign in with a Global admin or an Exchange admin account.
Go to Protection> Spam filter. Click on Default
Go to Allow Lists, and click on ‘+’ icon to add an email address for a domain. Once done click Save