No SMS on landline phones(not mobile)

First of all, nice work on the new and improved Contact system.

Our request is to add another type of phone number, something line “Landline” that we can input the customers landline phone number and on that type the system will not attempt to send automated SMS notifications.
Now if you have a landline phone number as any type the system will attempt to forward the SMS send request to the gateway, the gateway will attempt to send the SMS to the landline phone number, fail, and still charge your account, and in many cases allot of credits in the attempt.

Thanks