Basic Authentication Retirement for Legacy Protocols in Exchange Online

What does it mean that Microsoft retires basic authentication for legacy protocols in Exchange Online and how do it affect me?  

Microsoft has made the following announcement:  

Beginning October 13, 2020, we will retire Basic Authentication for EWS, EAS, IMAP, POP and RPS to access Exchange Online. Note: this change does not impact SMTP AUTH. 

What it means is that applications using those methods of communicating with Exchange Online will stop to work. For an example this could be mail apps, calendar apps and productivity apps. Microsoft recommendation is to move to Modern authentication (that is based on OAuth).  

So, how do I know if this affects me? Not at all until at least October 13, 2020. However, it could be good to be prepared and check which applications use Basic Authentication against these protocols. Right now, you must manually check which applications you use. However, Microsoft has committed to making a report that will let administrators check which connections is made with basic authentication.  

And for the companies running Exchange On-Prem? As Graph and Modern authentication is only available in Exchange Online, the way of integrating with Exchange On-prem will continue to be EWS and Basic authentication until Microsoft says anything else. As Microsoft wants to push companies into Office 365 it might be that there not will be any other way of integrating at all.   

How does it affect Meetio applications?  

All Meetio applications are ready for this. If you aren’t already on the new Office 365 connector based on Modern authentication you might have to update your Meetio software and create a new connector that is based on Modern authentication before October 13, 2020.  

Meetio Room, Meetio View and Meetio App support both basic authentication against EWS and Modern authentication against Office 365 Graph API so these applications are future proof (and still work with Exchange On-prem).  

Meetio Look supports only Exchange Online (through Modern authentication and Office 365 Graph API).  

Sources:  
https://techcommunity.microsoft.com/t5/Exchange-Team-Blog/Upcoming-changes-to-Exchange-Web-Services-EWS-API-for-Office-365/ba-p/608055 

Read more about Microsoft and its calendar systems here.