Question

Has anyone ever tried sending emails using 1&1 smtp host? I tried the following?

SmtpClient mailClient = new SmtpClient("smtp.1and1.com", 587);
mailClient.Credentials = new NetworkCredential("[e-mail]", "password");

But it always gives me a security exemption error…

I tried it using my local host and it works fine.. I tried using gmail’s smtp and it worked fine as well.. It says that I need to authenticate in order to use the smtp server, I did that by looking at the code above… Here’s the exact error:

Security Exception

Description: The application attempted
to perform an operation not allowed by
the security policy. To grant this
application the required permission
please contact your system
administrator or change the
application’s trust level in the
configuration file.

Exception Details:
System.Security.SecurityException:
Request for the permission of type
‘System.Net.Mail.SmtpPermission,
System, Version=2.0.0.0,
Culture=neutral,
PublicKeyToken=b77a5c561934e089’
failed.

Answer 1

You need to authenticate to send SMTP mail (Point 2a from their FAQ)