SMS Messaging Unknown Phone Type
When given a database list from a client, it is still possible that the phone number given is not a mobile number. This could result in the inability to receive SMS messages during your Database Reactivation.
So, should you worry?
The answer is, no. Twilio will simply send you a 404 Error Message. You can then choose to call that phone number through GHL's call capabilities or use another form of contact for this contact. It is important to note that this has no impact on your credibility with Twilio and will not be flagged for any reason in their system.