Quick answer
Official ID-checking objective
Mail or Jail's official Roblox description identifies customer IDs as part of the delivery loop. Check the customer ID while completing deliveries; it does not publish a recognition rulebook or score formula.
For mail or jail customer IDs, use the official objective: deliver mail and check customer IDs during a shift. The available official source does not document which ID details are accepted, how recognition works, or the exact penalty for a wrong check, so this guide does not invent those rules.