Office 365 authentication failing

Help
#1

I am trying to authenticate my Office 365 account. I get the following error.

It takes me through the OAuth process, I add my password and then I get this.

Authentication Error - Check your username and password. (SMTP)

I just paid my $8 a month yesterday so pretty disappointed this is not working.

#2

I’m getting the same error - I’ve authenticated multiple times and each time when I go back to MailSpring, it says “Sorry, we had trouble logging you in - Authentication Error - Check your username and password. (SMTP)”
Can this client link to O365?

#3

I subscribed and now cancelled as this error has been pending for weeks. Pretty useless frankly, a key platform that needs connecting.