txt.att.net outage?

Fri Jan 20 21:08:29 UTC 2023

It appears that Simmons, Jay via NANOG <jsimmons at semmes-murphey.com> said:
>-=-=-=-=-=-
>This may be the issue

Sorry, but no.

>Here are some details on this Government protocol implemented by all Telecom Carriers.
>
>Why it is being done? To support FCC mandate for STIR/SHAKEN, an industry set of rules designed to authenticate
>and validate CallerID information associated with phone calls using digital signatures.
>
>SHAKEN/STIR ...

STIR/SHAKEN only affects voice calls.  It has nothing to do with SMS.

As several other people have said, if you're sending safety critical SMS messages, use
a real SMS service, not a carrier's courtesy low volume e-mail gateway.

SMS services are not free, but they are not expensive, typically about 1/2 cent per message.

R's,
John