XOLBY may have SMS validation enabled, allowing XOLBY to check phone numbers for you at the time of SMS sending. If activated, XOLBY will check Twilio Lookup (which charges per lookup) to see if the number is a landline and then XOLBY won’t send messages to it. Twilio Lookup can also invalidate non-existent numbers or badly formatted numbers.
NOTE: The validation is done at the time of SMS sending, not during Contact Record creation or importing.
You may set up a workflow trigger for the Twilio validation error to set up trigger action accordingly. This can help you determine what automation(s) you want to setup in case of an invalid number. For example, if you send a bulk SMS but XOLBY detects an invalid number, you may want XOLBY to send you a notification so you can email the affected contact(s). This is just one use-case, but there are many options you can completely customize.
Step 1: Setting Up the Workflow Triggers for Twilio Validation
https://www.twilio.com/docs/api/errors/21211
https://www.twilio.com/docs/api/errors/30006
Now you’re ready to use the number validation!