Thailand Post is the semi-privatized national postal service in Thailand. Sadly, all of their web sites seem to be dead. They offer a full range of services, from regular air mail to express post. Most hotels can handle postage for post cards and letters to any country in the world. For more complicated requirements, you'll find post offices in almost all airports, or, you can find postal service companies in many shopping malls. These services can deal with all postal services as well as express courier services such as UPS.