3/27/2024 1:00 pm EDT: AT&T Multimedia Messaging

Alarm.com is investigating an issue where subscribers using a AT&T mobile phone may experience delayed or missed delivery of text message notifications that contain multimedia attachments (MMS).

Missed or retried deliveries may also cause “Delivery Status Notification (Failure)” messages to be returned for partners using Custom From Addresses for notifications.

They are working with the carrier to resolve this issue and will give an update as soon as possible.