text: 'use strict';
  
  module.exports = {
    // @see https://www.twilio.com/docs/api/messaging/message#delivery-related-errors
    undeliverableErrorCodes: {
      21203: 'International calling not enabled',
      21211: 'Invalid \'To\' Phone Number',
      21606: 'The \'From\' phone number provided is not a valid, message-capable Twilio phone number.',
      21610: 'Message cannot be sent to the \'To\' number because the customer has replied with STOP',
      21612: 'The \'To\' phone number is not currently reachable via SMS or MMS',
      21614: '\'To\' number is not a valid mobile number',
      30003: 'Unreachable destination handset',
      30005: 'Unknown destination handset',
      30006: 'Landline or unreachable carrier',
    },
  };
  