Sometimes, every user faces this issue - cannot send or receive emails from Sbcglobal account, don't worry. Because this is major trouble and this issue arises when your account is not connected correctly. So, you can check your Sbcglobal email server settings and change the settings, then again send emails from Sbcglobal account.
Also read - https://getassist.net/sbcglobal-email-not-working-how-to-fix/