AT&T - US has scheduled a maintenance. 

Start Time: 2022-11-08 04:00 UTC
End Time: 2022-11-08 12:00 UTC 

Impact MT: Clients may experience delayed/rejected/failed Short Code/10DLC SMS and MMS MT traffic towards AT&T
Impact MO: Clients may experience delayed/rejected/failed Short Code/10DLC SMS and MMS MO traffic from AT&T
Impact DLR: Clients may experience delayed/rejected/failed Short Code/10DLC SMS and MMS DLR traffic from AT&T