Test System.Net.Mail.SmtpClient settings without sending an email

Question

Hi! At first glance my question is very similar to this one, but it is different.

In my ASP.NET application user can save all settings necessary for sending an email (host, port, user name, password), and then send messages to other users using this settings whenever he wants. Please note that email isn't actually sent when user saves the settings he provided. Therefore I need to find another way to test whether provided settings are correct (instead of catching an exception after sending an email).

Good example that this is possible can be found in gmail. There is an option in gmail that allows you to collect mails from other accounts. When you specify host, port, username and password, gmail immediately tests connection and informs you if the test failed. This behavior is smth that I need.

Thanks in advance.

Answer 1

Got this post while searching. See if it helps

Validating SMTP host information

The idea is simple, open a TCP connection to the host, and read the initial welcome message sent by the smtp host, it should start with response code 220.