Your launch data clearly states that version 10 is compatible with Outlook and other Microsoft systems.
Does this mean that the problem relating to authentication discussed here about eM Client 9 - Microsoft and basic authentication - personal outlook accounts
– has now been resolved?
Yes eM Client V9 & V10 both support Microsofts IMAP, Exchange, Outlook 365:accounts where you add your MS account via the “automatic account wizard” in eM Client using the OAuth token login, where at the end of the wizard you click allow on the MS popup message to give eM Client access to your Microsoft account.
If you have an old legacy MS account that logged in manually with a username and password and you are now getting asked for a username and password prompt, then you will need to readd your same MS account again via the eM Client automatic account wizard via “Menu / Accounts”, and then drag / move all your existing mail and any custom mail folders to the new account.