The reason behind stopping this is that it will prevent accounts from being brute-forced or falling victim to password spray attacks. But Microsoft has now set a definite date, announcing that “effective October 1, 2022, we will begin to permanently disable Basic Auth in all tenants, regardless of usage, with the exception of SMTP Auth.” What does this mean for you? For those new to Microsoft 365, basic authentication allows users to connect to a mailbox using only a username and a password. With COVID changing everything, the deadline was postponed. Microsoft announced back in 2021 that they would be turning off basic authentication for all Exchange Online tenants in Microsoft 365.
