Here are some basic email troubleshooting steps:
1. Make sure that there is an Internet connection. This can be done by power cycling the modem and PC at least once.
2. Check all email client settings: Username, Password, Incoming email server (mail.domain name.net), and Outgoing email server (mail.domain name.net).
3. Check online at the email web server to make sure the account can be accessed through the web server directly.
4. Temporarily disable any anti-virus or firewall protection. It could be set too high to let email traffic through. The settings for the program will need to be checked if that is the case.