A number of factors could prevent contacts from receiving email/SMS campaign notices:

• Check whether the contact(s) are active
  • Many rewards programs deactivate a contact after a specified number of days of inactivity
• Verify the contact(s) email/SMS information
• Verify the contact matches the selection criteria in a segment or list
• Verify the email/SMS broadcast date (confirm it is active)
• Verify the business/rewards program(s) haven't exceeded their Email/SMS credits

Check other settings in the rewards program, contact list, and campaign