C#

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. C#

bool success = 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"
//  	}
//  
Chilkat.JsonObject json = new Chilkat.JsonObject();
success = json.LoadFile("qa_data/tokens/_gmailSmtp.json");
if (success != true) {
    Debug.WriteLine("Failed to load GMail access token file.");
    return;
}

string accessToken = json.StringOf("access_token");

Chilkat.MailMan mailman = 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
Chilkat.Email email = 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) {
    Debug.WriteLine(mailman.LastErrorText);
    return;
}

//  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) {
    Debug.WriteLine("Connection to SMTP server not closed cleanly.");
}

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