venkatrangan

Hi, I am trying to use NTLM authentication with the HTTP Client 4.4.1 and it is failing with 401 Unauthorized. The same user format (domain\user) using external Microsoft connectivity tool...

Per this blog, EWS will EOL Basic Authentication. Before that, the OAuth support should be included: https://blogs.technet.microsoft.com/exchange/2018/07/03/upcoming-changes-to-exchange-web-services-ews-api-for-office-365/