If you have a Frontier (or Comcast) account you will have to add the Frontier outgoing server. Here are the basic instructions but you should refer to Fontiers instructions (try Googling "setting up email with Frontier") in case they may have changed their system:
1. Select (Add Server)
2. Host Name: smtp.frontier.com
3. User Name: Must be the "Frontier" user name for their email account on "Frontier" the entire name
4. Password: Must be the "Frontier" user name for their email account on "Frontier"
5. Use SSL: must be turned on
6. Pasword Authentication
7. Server Port: 25
8. Next select the ( mail.zaks.com )server and turn it (off).
9. Next select the ( smtp.frontier.com ) and turn it (on).