We are having trouble connecting to outlook.office365.com with OAuth2.0.
After getting a valid accessToken we do this:

lMailServer.Server = 'outlook.office365.com'
lMailServer.Port = '443'
lMailServer.User = '[our username]'
lMailServer.Password = accessToken
lMailServer.Protocol = 2 // EWS
lMailServer.SSLConnection = TRUE
lMailServer.AuthType = 3 // OAuth
lMailServer.Alias = "[email address]"
lmailClient.Connect(lMailServer)

Last line fails with "Unknown error 500".
My concern is that despite the authtype being set to 3 the log file shows this:

Server: outlook.office365.com
Port: 443
AuthType: AuthLogin
SSLConnection: True
SSLType: ConnectSSLAuto
Protocol: Exchange Web Service
ProxyProtocol: Socks5

AuthLogin is from an error of log writter, could you send more detail to our support email address for assistance?

Apparently the issue was related to TSL1.2 support in Windows 7. It's now resolved, thank you so much.