We got an option to retry sending to multiple, when it fails (typically mms).

BUT Currently it retries sending to ALL!

I would suggest using the list it already got with check marks and exclamation on the one that failed, and
1) Send to those that have not been sent to first
2) Then retry to the individuals marked with exclamation point it failed on
3) If more retries are needed, the list is likely to be reduced gradually.