AT&T has reported the issue is resolved and message delivery to Mexico is no longer experiencing delay.
Posted Nov 20, 2019 - 15:38 PST
AT&T is currently experiencing a service disruption in Mexico which is causing delayed message delivery to all destinations in Mexico. AT&T is actively working towards a solution. We will provide an update shortly.
Posted Nov 20, 2019 - 14:11 PST
This incident affected: CARRIER NETWORK (SMS, Latin America).