You may need to turn off birthday notifications for contacts in Outlook. Follow the instructions below to turn off birthday notifications:

Note: You must have an Office 365 account. The setting cannot be changed from the Outlook desktop client. 

1. Log in to your Office 365 account.

2. Click on Outlook. 

3. a. Click the Settings gear icon.

    b. Click View all Outlook Settings. 

4. Click on Calendar. Click View.

5. Under the Birthday calendar section at the bottom of the screen, uncheck the box for Turn on the birthday calendar. Click Save.

You will no longer receive birthday notifications.