your computer or phone) and a server, as well as some security measures that rely on access policies that you may already be familiar with like Multi-Factor Authentication. Modern authentication is an umbrella term for a combination of authentication and authorization methods between a client (eg.

The need for more robust security led to the creation of Modern Authentication. Unfortunately, hackers have found many ways to exploit this authentication scheme and it is no longer safe to use.

Basic Auth, in this scope, was the simple handshake between your Outlook client and Microsoft’s email servers and has been in use since 1996. Why is this happening? Simple really, advancement and improvement of security. After that, it is up to Microsoft’s discretion whether they continue allowing it to connect to Microsoft 365. All versions prior to 2013 have already been deprecated and are no longer supported by Microsoft 365.įor users running Outlook 2013 it is highly recommended that you begin the upgrade process to a newer version of Microsoft Office as that product will be “end of life” as of April 2023. Additionally, if you have an older PC that has upgraded from Office 2013 (Office 2013->2016->2019), then authentication may also break. Anyone running Outlook 2013 will no longer be allowed to sign in to their email.

As of January 2023, Microsoft has turned off Basic Authentication for Microsoft 365.

Office 2013 modern authentication