Microsoft rules will move all potential junk email to your Junk Email folder. It's important you check this folder regularly to ensure you are not missing any emails, by regularly monitoring this folder and tagging emails that are "not junk" you update the list of email addresses and domains that you do and don't trust.
Add the steps involved :
Check this folder at least weekly to make sure no legitimate emails have been moved accidentally to this folder:
If there is a legitimate email in your Junk Folder, right click on the email
- Select Junk
- Select Not Junk
Check Always trust email from “email address”
You can also tag all emails from this domain as "safe" by selecting "Never Block Sender's Domain (@example.com):