Starting from Adaxes 2023.2, Adaxes uses the EXOv3 PowerShell module for all operations in Exchange Online. This means basic authentication in WinRM can be disabled on the computer where Adaxes service is installed.
However, earlier versions of Adaxes used PowerShell remoting to perform operations in Exchange Online. If basic authentication in WinRM was disabled, you would encounter the following error message:
Connecting to remote server outlook.office365.com failed with the following error message: The WinRM client cannot process the request. Basic authentication is currently disabled in the client configuration. Change the client configuration and try the request again.
If you see this error message, you need to enable basic authentication in WinRM. Basic authentication will not be used to send your username/password combination in plaintext over the internet. Even in versions before 2023.2, Adaxes connected to Exchange Online using modern authentication based on OAuth. Basic authentication was required to send the session's OAuth token because the client-side implementation of WinRM does not support OAuth.