Announcing OAuth Support for POP in Exchange Online

Hi crshan,

I've registered my app on Azure and have enabled API Application Permissions for MS Graph( POP.AccessAsUser.All, User.ReadBasic.All, User.Read.Write) for pop3 and

Added below scope 

"https://outlook.office.com/POP.AccessAsUser.All%22 explicitly in the code during acquire token.

and below is pseudo code in c#

private readonly string[] Scopes = new string[] { "https://outlook.office.com/POP.AccessAsUser.All" };
private const string LoginURI = "https://login.microsoftonline.com/";

m_clientApp = PublicClientApplicationBuilder.Create(m_mailAccount.ClientID)
.WithAuthority($"{LoginURI}{m_mailAccount.TenantID}")
.WithDefaultRedirectUri()
.Build();

AuthenticationResult authResult = null;

authResult = m_clientApp.AcquireTokenSilent(Scopes, existingUserID).ExecuteAsync().Result;