The request failed. The remote server returned an error: (401) Unauthorized.

Question

Hi,

Trying to connect to the EWS - The request failed. The remote server returned an error: (401) Unauthorized. - is the error message.

Using the TestConnectivity test, the error is the below code.

My problem is, my mails are hosted with Office itself and I cannot seem to find a solution.

Answer 1

Try to disable MFA and check.

Basic authentication in now disabled by default in Office 365, so you should avoid using it. Look at implementing oAuth in your see code https://learn.microsoft.com/en-us/exchange/client-developer/exchange-web-services/how-to-authenticate-an-ews-application-by-using-oauth