When a phone number is added to a contact, Kolleno checks whether it's a mobile, landline or VoIP number. This decides what happens when an SMS is sent.
Workflow and bulk SMS
Landline and VoIP numbers are skipped. Kolleno never sends to them.
No valid mobile number: a note is added to the customer's timeline and the workflow tries again on its next runs, until a valid mobile number is added.
Number sent but rejected straight away: handled the same way. A note is added and the workflow retries.
Number sent but not delivered: the SMS is marked Undelivered and the workflow moves on without retrying. Use the SMS undelivered trigger to follow these up.
Manual SMS
SMS sent by a user from a contact or Task Manager aren't checked for number type, so they can be sent to a landline. If the SMS is rejected, the user sees an error straight away. If it isn't delivered, it shows as Undelivered. Manual SMS are never retried.
Does a failed SMS count towards my allowance?
No. Only SMS marked Sent, Delivered or Delivered & clicked count towards your monthly allowance.