Happy Marketers has built-in double texting protection, which prevents numbers from being texted twice within 10 hours.
How does this double texting protection work exactly?
Once a campaign is sent, Happy Cabbage checks against a table that has 10 hours worth of attempted phone numbers saved for your organization. We remove numbers from the currently sending campaign that are in that table, and we also add the new numbers from this campaign with a datetime and org stamp.
Numbers are removed from this table after 10 hours, or if Happy Cabbage gets confirmation from our message aggregator that a message failed to deliver to that phone number.
The double text protection tables are org specific, in case you share a mutual customer with another org using Happy Cabbage.