Message couldn't be delivered to the recipients number you are trying to reach at this time due to local regulatory restrictions.
Marketing, promotional & other non essential messages are restricted under the local regulatory requirement (e.g.TCPA in US) to certain hours of the day. Specifically, these communications cannot be made before 8 a.m. or after 9 p.m. local time at the recipient's location. This restriction is intended to protect consumers from intrusive communications during times they are likely to be resting or engaged in personal activities.
Verify Local Time: Implement a system to accurately determine the local time zone of each recipient based on their area code and address data.
Schedule Adjustments: Configure your messaging campaign schedules to operate only within the permitted hours of 8 a.m. to 9 p.m. local time for each recipient.
Twilio's support team can help investigate what went wrong with delivering your message. Please collect 3 or more message SIDs in your SMS logs from the last 24 hours that were flagged with Error 30615, and open a support request.