Testing Sendgrid SMTP without sending emails using sandbox mode

Mar 03, 2019
sendgrid c-sharp
1 min read

Here’s how to test out a Sendgrid integration using SMTP without actually sending emails. Obviously make sure you have Sendgrid SMTP set up in your config first, and then just add the X-SMTPAPI header (docs link) with some JSON like the below.

MailMessage msg = new MailMessage();
var json = @"{
    ““mail_settings”": {
        ““sandbox_mode”": {
            ““enable”": true
        }
    }
}";

msg.Headers.Add(“X-SMTPAPI”, json);
// all the usual email stuff

SmtpClient smtpclient = new SmtpClient();
smtpclient.Send(msg);