First of all, Open the settings of your Desktop.
Now you can see mail option on the screen, click on it.
You can see the list various mail account, ignore them and click on the add account.
Click on the Other mail option and then click on the add email account.
Now type your SBCGlobal email id and then type your Password.
Type SBCGlobal email on the description field.
Click on the next button and choose the “POP” option that appears button of the Screen and fills these Sbcglobal IMAP/ POP Email Settings carefully:-

Email settings
Sbcglobal, Bellsouth, ATT.net email settings
AT&T IMAP Server
imap.mail.att.net
IMAP port
995 or 993
IMAP server
SSL / TLS
IMAP username
Your full email address
IMAP password
Your Sbcglobal.net password

AT&T SMTP Server
smtp.mail.att.net
SMTP port
465 or 587
SMTP sec.urity
SSL / TLS
SMTP username
Your full email address
SMTP password
Your Sbcglobal.net password

After filling these settings now you have to type the server name:-
Server Type: POP3

Type incoming mail server: pop.sbcglobal.yahoo.com
And after that type outgoing mail server: smtp.sbcglobal.yahoo.com
Once you type the servers name you have to fill these Sbcglobal IMAP/ POP Email Settings:-
Enter your username
Enter your password
Enter pop3 server - pop.att.yahoo.com or pop.sbcglobal.yahoo.com
Enter Port - 995 or 993
Touch Next
Enter SMTP server - smtp.att.yahoo.com or smtp.sbcglobal.yahoo.com
Enter Port - 465 or 587
Enter your username
Enter your password
Touch Next

Sometimes users face errors while they are using SBCGlobal email account on MacBook. So here we discussed reasons of those errors and how to solve Sbcglobal IMAP/ POP Email Settings.
Resolve SBCGlobal email account Errors into Sbcglobal IMAP/ POP Email Settings:-

Open the mail option from your system's setting
Click on the preferences from the drop-down window.
Open that email account which accounts you are facing the error.
After that open the advanced settings from the main menu.
Click on Automatically detect mail settings box. After that uncheck the box and type the settings carefully.
Now restart your SBCGlobal email login app.
Clear your browser cache and cookies.
I hope now you can use SBCGlobal email login account without any errors.