Safe sender and blocked sender lists in Exchange Online

Exchange Online

Applies to: Exchange Online, Exchange Online Protection

Topic Last Modified: 2018-05-22

As an Exchange Online or Exchange Online Protection (EOP) administrator, you can help ensure that an email message traveling through the service isn’t marked as spam. One way to do this is to create safe sender and blocked sender lists for the people in your organization.

See the updated version of the tips and procedures for how to work with these lists as an admin in Prevent false positive email marked as spam with a safelist or other techniques.

If you're not an admin, and you just want to manage your own junk email in Outlook by using a safe sender list, check out the steps in this overview of the Junk Email Filter.

The safe and blocked sender limits in Exchange Online differ from the Active Directory and Outlook limits. They are:

  • Safe sender limit is 1024

  • Blocked sender limit is 500