Don't expect the services of a town. Boca Chica is more developed and likely to have what you want in the way of services. Most hotels, at least at the big resorts, will exchange either U.S. or Canadian dollars into pesos. If you need to mail something, ask at your reception desk. The staff there will most often turn your mail over to a local carrier when he passes through. Only the first-class all-inclusives sell postage stamps. Most hotels provide laundry service.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.