Your desktop ATT email program or mobile email app will use either IMAP or SMTP to send and receive the email. Always make sure to use the right server and port settings to make the process more comfortable and smother. By doing the right IMAP and SMTP server configurations, you can check your emails and send messages by using other email programs including Mail spring, Outlook Express, Apple Mail, or Mozilla Thunderbird on your smartphone. Check the complete information regarding Bellsouth.net email server settings below in this guide.