Well, it's not just power messenger that is hanging on trying to send to that email address. It is also the Network solutions script that is hanging.
it is hanging when trying to connect to the SMTP server.
The SMTP server should not hang up if the email address is not valid, it should just reject the email and move on, it should send a bounce back notice.
the problem is that instead of sending a bounce back notice the SMTP server is hanging.
Both the network solutions script and power messenger are using the same method to connect to the smtp server and send the message. the SMTP server should not be stalling on an email address that doesn't exist.