Mac Mail (OS 10.0-10.2 Jaguar)

Open the Mail Program.
Click on Mail and select Preferences.
Click the Accounts icon.
Select your email account from the pane on the left and click the Edit button on the right.
At the bottom of the Account Information page, under the Outgoing Mail Server field, click the button labeled Options....
On the SMTP Server Options screen, enter smtp.gvtc.com for the Outgoing Mail Server.
There will be a field labeled Authentication with a drop-down field to the right. Select Password from the options in the drop-down field.
In the User Name field, type your email username and put your email password in the Password field.
Click OK.
Close all settings windows to return to Apple Mail and you're done!