Great wiki page on SMS message regulations.
Regulations and best practices for SMS messages are governed by the Mobile Marketing Association, which publishes a code of conduct and a best practices guide for use by those involved in mobile messaging activities. Ultimately, all SMS messages sent using Recess Mobile applications must include the following elements.
Double-Opt In
Your SMS messages must include a double opt-in process, where the subscriber confirms twice that they wish to receive SMS messages from you. For example, an MO JOIN message would prompt the following MT reply:
Reply YES to receive Example.com Sales. 1 or more msgs/day 4 desired alerts. Reply STOP 2 end. HELP 4 info. Msg&Data Rates May Apply.
From there, a MO YES message would prompt the following MT reply:
Your 1st alert will arrive soon. Reply STOP to end, Help 4 info. Msg&Data Rates May Apply.
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