I have a standard Google Apps account. I have setup a custom domain through Google Apps. I am able to send and receive emails successfully through Google Apps when I use the Gmail interface. However, I want to send an email via code. In order to attempt this, I have been trying the following code:
MailMessage mailMessage = new MailMessage(); mailMessage.To.Add("someone@somewhere.example"); mailMessage.Subject = "Test"; mailMessage.Body = "<html><body>This is a test</body></html>"; mailMessage.IsBodyHtml = true; // Create the credentials to login to the gmail account associated with my custom domain string sendEmailsFrom = "emailAddress@mydomain.example"; string sendEmailsFromPassword = "password"; NetworkCredential cred = new NetworkCredential(sendEmailsFrom, sendEmailsFromPassword); SmtpClient mailClient = new SmtpClient("smtp.gmail.com", 587); mailClient.EnableSsl = true; mailClient.DeliveryMethod = SmtpDeliveryMethod.Network; mailClient.UseDefaultCredentials = false; mailClient.Timeout = 20000; mailClient.Credentials = cred; mailClient.Send(mailMessage);
When the Send method is reached, an Exception is thrown that states:
"The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required."
How do I send emails through my custom domain via Google?
There is no need to hardcode all SMTP settings in your code. Put them in web.config instead. This way you can encrypt these settings if needed and change them on the fly without recompiling your application.
End when you send email just enable SSL on your SmtpClient:
Make sure that you’re sending email from the same email address with which you’re trying to authenticate at Gmail.
Note: Starting with .NET 4.0 you can insert
enableSsl="true"intoweb.configas opposed to setting it in code.