Legacy or basic authentication is a name Microsoft uses to refer to older authentication methods for accessing its applications and systems, specifically email. These legacy authentication methods do not support newer security features, such as Multi-Factor Authentication, so they are less preferred.
Microsoft is deprecating the use of legacy authentication methods
Due to this planned deprecation and related security concerns of using legacy authentication, Seattle University will require users to switch to more secure methods of accessing their Seattle University email
If Seattle University detects that your account is using legacy authentication, you should receive an email with instructions on how to update the method you use for connecting to your SU email.
You can check this list of impacted systems to see if you may still be using legacy authentication
If you are still using legacy authentication when it is deactivated, then you will receive this email blocked message