Basic Authentication for All Exchange Online Tenants Stops (with no exceptions) in October 2022

[TonyRedmond]

October 1, 2022 will be a big day for Exchange Online tenants because that’s when Microsoft starts to disable basic authentication for connectivity protocols whether or not tenants want this to happen. This is a huge and fundamental change that’s being driven by the need to increase the overall security of Exchange Online and individual tenants, while also blocking common attacks seeking to compromise user accounts. With only a year to go, it’s time to start work on preparing everything that needs to be in place for the great October 1 switchoff.

https://office365itpros.com/2021/09/24/basic-authentication-exchange-online-tenants-stops-october-20...

[#2]

More detail about the SMTP AUTH exception Microsoft has made:

SMTP AUTH Exception Smoothens Path to Removal of Basic Auth in Exchange Online

Last week’s announcement that Exchange Online will block basic authentication for multiple protocols on October 1, 2022, got some attention. Now the hard choices of what to do with clients and applications need to be made. To smoothen the path to remove basic authentication, Microsoft is making an exception for SMTP AUTH. Your scripts and multi-function devices will keep working after October 2022, but the writing is on the wall and eventually even SMTP AUTH will stop working.

https://office365itpros.com/2021/09/27/basic-authentication-disappears-exchange-online/