(.NET Core C#) Office365 POP3 Login with OAuth2 Authentication

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Demonstrates how to authenticate using OAuth2 using the POP3 protocol with outlook.office365.com.

Note: This example requires Chilkat v9.5.0.83 or greater.

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// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Chilkat.MailMan mailman = new Chilkat.MailMan();

mailman.MailHost = "outlook.office365.com";
mailman.MailPort = 995;
mailman.PopSsl = true;

// Use your O365 email address here.
mailman.PopUsername = "OFFICE365_EMAIL_ADDRESS";

// When using OAuth2 authentication, leave the password empty.
mailman.PopPassword = "";

// Load our previously obtained OAuth2 access token.
Chilkat.JsonObject jsonToken = new Chilkat.JsonObject();
bool success = jsonToken.LoadFile("qa_data/tokens/office365.json");
if (success == false) {
    Debug.WriteLine(jsonToken.LastErrorText);
    return;
}

mailman.OAuth2AccessToken = jsonToken.StringOf("access_token");

// Make the TLS connection to the outlook.office365.com POP3 server.
success = mailman.Pop3Connect();
if (success != true) {
    Debug.WriteLine(mailman.LastErrorText);
    return;
}

// Authenticate using XOAUTH2
success = mailman.Pop3Authenticate();
if (success != true) {
    Debug.WriteLine(mailman.LastErrorText);
    return;
}

// Find out how many emails are on the server..
int numEmails = mailman.CheckMail();
if (numEmails < 0) {
    Debug.WriteLine(mailman.LastErrorText);
    return;
}

// Examine the POP3 session log:
Debug.WriteLine(mailman.Pop3SessionLog);

// The POP3 session log will look something like this:

// **** Connected to pop.gmail.com:995
// < +OK The Microsoft Exchange POP3 service is ready. [QwBIADIAUABSADEAOABD...YwBvAG0A]
// > AUTH XOAUTH2
// < + 
// > <base64 string in XOAUTH2 format>
// < +OK User successfully authenticated.
// > STAT
// < +OK 3 375302

// End the POP3 session and close the connection to the GMail server.
success = mailman.Pop3EndSession();
if (success != true) {
    Debug.WriteLine(mailman.LastErrorText);
    return;
}

Debug.WriteLine("Finished.");