Today, we are announcing that on October 13th, 2020 we will stop supporting and retire Basic Authentication for Exchange Active Sync (EAS), Post Office Protocol (POP), Internet Message Access Protocol (IMAP), and Remote PowerShell (RPS) in Exchange Online. This means that new or existing applications using one or more of these API’s/protocols will not be able to use Basic Authentication when connecting to Office 365 mailboxes or endpoints and will need to update how they authenticate. //

we are making significant investments to our service that include OAuth 2.0 support for POP, IMAP, and background application support for Remote PowerShell MFA module. We will be sharing more information on these new features over the coming months. For more information on OAuth 2.0 and details on how to make the transition, please refer to the following articles:

Microsoft identify platform (v2.0) overview
Getting started with OAuth2 for Microsoft Graph

https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-overview

https://developer.microsoft.com/en-us/graph/docs/concepts/auth_overview