Untitled

🧩 Syntax:
I send emails to my "Joke Group" a couple of times a day.  The group has 25 - 30 email addresses in it.
Now, I get a notice that 4 emails, being sent to ****@sbcglobal.net have not been delivered.
All other emails have been delivered, just the ones addressed to sbcglobal.net have not.
Can you explain why?