Between approximately 10:15AM US Pacific time on 17 March and 2:22PM US Pacific time on 18 March, mobile-originating SMS messages (from end users) were not being delivered correctly, which may have resulted in missed messages back to end users and missing opt-outs. Other SMS/MMS messages continued to be processed and delivered normally. This was due to a bug in a code change that was deployed on the 17th when the issue began. We are currently working with our SMS provider to obtain the lost data so we can update any missing opt-outs for customer devices as soon as possible. We will also be adding monitoring to detect a similar problem more quickly in the future. We apologize sincerely for the inconvenience.