[solved]Unable to read data from the transport connection: net_io_connection closed.

When you try to send an email from web application if you got exceptions like this check your Username or password it must be wrong verify and correct it.Also Check port number if it is 465 (SSL) change to 80. To find them, go to the Email Setup Center and login to your account using godaddy.

you can also check these links hope these are help you...

 http://www.infinetsoft.com/Post/How-to-configure-godaddy-email-account-using-net/56