Do you have a link to this notice? Microsoft has been pushing to disable basic authentic for some time because of security around it. The replacement is to use

Do you have a link to this notice? Microsoft has been pushing to disable basic authentic for some time because of security around it. The replacement is to use oauth2. Is that what's actually going on here? https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/deprecation-of-basic-authentication-exchange-online https://learn.microsoft.com/en-us/exchange/clients-and-mobil... It wouldn't shock me that developers have ignored this. Really you should be questioning the app for not keeping up with modern methods instead of bashing MS on this point.