Birdeye launched feature to indicate business users who may check-in contacts with inaccurate information (e.g. a contact's number may not be a valid mobile number or might be a landline number). Any SMS attempt on these numbers will fail and hamper Campaign results.
Once a phone number is added and an SMS is attempted to be sent on that number, the system will check if it's a valid mobile number or not. If not, the system will flag that number by marking the number in red.
This will be indicated on the contacts page and will also be displayed on the edit contact page. It ensures that a user is informed about the incorrect data and can update the number again and attempt sending an SMS again.