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Legacy Authentication - End of Life

M365 Legacy Authentication End of Life – October 2022

On October 1st, 2022, Microsoft will block accounts using legacy authentication protocols for authenticating against Microsoft 365 services such as Email, Teams, OneDrive for Business, etc.

For most accounts this won’t have any impact since most Email clients are already using modern authentication protocols. For users connecting using the older authentication methods this change will prevent access.

What ECS is doing

  1. Starting in July a conditional access policy will be put in place that will block accounts from logging into M365 using legacy authentication.
  2. Accounts currently using legacy authentication will be excluded from the policy to avoid service interruption.
  3. Local IT Support and the ECS team will communicate with users who are still using legacy authentication and provide information on updating their email clients to use modern authentication protocols.
  4. Before the October 1st, 2022, deadline all legacy authentications will be blocked for M365. Once this occurs email clients using legacy authentication protocols will no longer have access to M365 services.

How will someone know if they are being blocked due to an email client using legacy authentication?

When attempting to access email they may see an error message like the following:

"Your email access has been blocked. You are receiving this message because your IT department has blocked your email access. This could be due to temporary conditions, like your network location Contact your IT department with any questions or concerns about this mail. This email was automatically generated by Microsoft Exchange."

How does someone update to modern authentication?

  • Most email clients can now utilize modern authentication. If the account profile was configured in the application using basic/legacy authentication the profile may need to be recreated to use modern authentication.  Visit the vendors website for your product to find out more.
  • If the application doesn’t support modern authentication use the official Outlook email client, if available.
  • The web version will utilize modern authentication and can be accessed at webmail.untsystem.edu.

More Information

Microsoft info page about the change.

Security reasons to move away from basic authentication.