As of Wednesday, September 30th, AT&T may increase its blocking of messages, including political messaging, and/or associated telephone numbers sending messages to AT&T subscribers. These guidelines apply to all messaging channels including local (10DLC), toll-free, and shortcode.Types of messages subject to being blocked:
- Fail to use opt-out notices (e.g., ‘reply STOP 2 end’) in all subscribed messages
- Include public URL shorteners
- Use spam filter evasion techniques, such as rapidly changing URLs or the use of unnecessarily large pools of sending numbers.