In response to the unprecedented situation we are in and knowing that priorities have changed for many of our customers we are suspending until further notice the disabling of Basic Authentication for any protocols that your tenant is using. This was previously communicated in Exchange Online (MC204828 and MC208814). When we resume this program, we will provide a minimum of twelve months’ notice before we block the use of Basic Auth on any protocol being used.
We will continue with our plan to disable Basic Auth for protocols that your tenant is not using. Many customers don’t know that unneeded legacy protocols remain enabled in their tenant. We plan to disable these unused protocols to prevent potential mis-use. We will do this based on examining recorded usage of these protocols by your tenant, and we will send Message Center posts providing 30 days’ notice of any changes to your tenant. This work will begin in a few months.