(VB.NET) POP3 GMail XOAUTH2 Authentication

Demonstrates using OAuth2 authentication with pop.gmail.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.

Dim mailman As New Chilkat.MailMan

mailman.MailHost = "pop.gmail.com"
mailman.MailPort = 995
mailman.PopSsl = True

mailman.PopUsername = "my_account@gmail.com"

' If using OAuth2 authentication, leave the password empty.
mailman.PopPassword = ""

' Load our previously obtained OAuth2 access token.
' See Getting a GMail POP3 OAuth2 Access Token
Dim jsonToken As New Chilkat.JsonObject
Dim success As Boolean = jsonToken.LoadFile("qa_data/tokens/gmail_pop3.json")
If (success = False) Then
    Debug.WriteLine(jsonToken.LastErrorText)
    Exit Sub
End If


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

' Make the TLS connection to the POP3 server.
success = mailman.Pop3Connect()
If (success <> True) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If


' Authenticate..
success = mailman.Pop3Authenticate()
If (success <> True) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If


' Find out how many emails are on the server..
Dim numEmails As Integer = mailman.CheckMail()
If (numEmails < 0) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If


' 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 Gpop ready for requests from 87.9.200.42 l16mb86351205iok
' > AUTH XOAUTH2 dXNlcj1....VaMDJFAQE=
' < +OK Welcome.
' > STAT
' < +OK 301 1627357
' 
' -- Finished.


' End the POP3 session and close the connection to the GMail server.
success = mailman.Pop3EndSession()
If (success <> True) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("-- Finished.")