1. Open Thunderbird and click on Tools and then Accounts Settings.
2. Click on the Server Settings.
3. Set your Server Name to pop.gmail.com. Set the Port to 995. Change your User name to your_username@tnetmail.net
4. Select TLS, if available.
5. Click Outgoing Server on the menu to the left.
6. Select your Outgoing Server and click Edit.
7. Enter the Server Name to smtp.tranquility.net. Set the Port to 465. Check Use name and password and enter your username. Finally select TLS.
Your screen should look like ONE of the images below:
8. Click OK, then OK again.