How can I log into gmail IMAP using MailKit - gmail

Question

I am trying to use MailKit (http://jstedfast.github.io/MailKit/docs/index.html) to log into Gmail using oAuth. I am able to log into Google API using a refreshed AuthToken, but when I try to use the refreshed token in MailKit, I get an error "Invalid Credentials"
Any clues??
Thanks,
Jeff
Here is my code:
var secrets = new ClientSecrets()
{
ClientId = "xxx-yyy.apps.googleusercontent.com",
ClientSecret = "xyzSecret"
};
IAuthorizationCodeFlow flow =
new GoogleAuthorizationCodeFlow(new GoogleAuthorizationCodeFlow.Initializer
{
ClientSecrets = secrets,
Scopes = new string[] { GmailService.Scope.GmailReadonly }
});
var tokenResponse = flow.RefreshTokenAsync("", connection.RefreshToken, CancellationToken.None).Result;
using (var client = new MailKit.Net.Imap.ImapClient())
{
var credentials = new NetworkCredential("emailtoconnect#gmail.com", tokenResponse.AccessToken);
client.Connect("imap.gmail.com", 993, true, CancellationToken.None);
try
{
client.Authenticate(credentials, CancellationToken.None);
}
catch (Exception ex)
{
throw;
}
}

Answer 1

a clearer answer is that the scope was incorrect in the original code
Scopes = new string[] { GmailService.Scope.GmailReadonly }
needs to be
Scopes = new string[] { GmailService.Scope.MailGoogleCom }
in order to authenticate with imapi using a access token.

Answer 2

It was just a scope problem. The above code works fine for gmail oAuth!!

Answer 3

using (var client = new ImapClient())
{
client.Connect("imap.gmail.com", 993, true);
client.AuthenticationMechanisms.Remove("XOAUTH2");
client.Authenticate(EmailId, Password);
}
The above piece of code is used to log in to gmail using imap and MailKit tool. But before this, you have to log in to gmail manually and check "Enable Imap" option in Settings. This will surely work.