Posted documents, for my wifes visa, to BKK last year and used DHL, picked up from home on the Friday and arrived in BKK on the Monday, £54, expensive but worth it, also she had to aign for them so I knew nobody else would get them. I sent a jiffy envelope of photos of our 2 month old son to wifes family in Nakhon Phanom 2 months ago, never to be seen again.

Never had any problems sending packages there. I send priority and fiancee gets it in about 2 weeks. Sending greeting cards is a different story. If I don't send them priority (costs $11 for one card) she NEVER gets them.