VB.NET

GMail SMTP Send using Previously Obtained OAuth2 Access Token

See more GMail SMTP/IMAP/POP Examples

Demonstrates how to send email using GMail and OAuth2 authentication. This example assumes an OAuth2 access token was previously obtained. VB.NET

Dim success As Boolean = False

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

' See Get GMail SMTP Access Token 
' for sample code showing how to obtain a GMail SMTP access token for desktop apps.

' In this example, our access token was previously saved to the following file which contains JSON like this:
' 	{
' 	 "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
' 	 "token_type": "Bearer",
' 	 "expires_in": 3600,
' 	 "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
' 	}
' 
Dim json As New Chilkat.JsonObject
success = json.LoadFile("qa_data/tokens/_gmailSmtp.json")
If (success <> True) Then
    Debug.WriteLine("Failed to load GMail access token file.")
    Exit Sub
End If

Dim accessToken As String = json.StringOf("access_token")

Dim mailman As New Chilkat.MailMan

' Set the properties for the GMail SMTP server:
mailman.SmtpHost = "smtp.gmail.com"
mailman.SmtpPort = 587
mailman.StartTLS = True

' The SMTP username should be the GMail address of the user's account that authorized your app to send email.
mailman.SmtpUsername = "chilkat.support@gmail.com"
mailman.OAuth2AccessToken = accessToken

' Create a new email object
Dim email As New Chilkat.Email

email.Subject = "This is a test"
email.Body = "This is a test"
email.From = "Chilkat <chilkat.support@gmail.com>"
email.AddTo("Chilkat Admin","admin@chilkatsoft.com")
' To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

' Call SendEmail to connect to the SMTP server and send.
' The connection (i.e. session) to the SMTP server remains
' open so that subsequent SendEmail calls may use the
' same connection.  
success = mailman.SendEmail(email)
If (success <> True) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If


' You may close the connection here.  If the connection is kept open, 
' the next call to mailman.SendEmail will continue using the already-established connection
' (and automatically re-connect if needed).
success = mailman.CloseSmtpConnection()
If (success <> True) Then
    Debug.WriteLine("Connection to SMTP server not closed cleanly.")
End If


Debug.WriteLine("Email Sent via GMail with OAuth2 authentication.")