Departing on Thai domestic to Bangkok. Plane delayed 2 hours due to congestion at Immigration. Phuket immigration cannot cope at busy times especially when everyone tries to clear immigration at Phuket instead of Bangkok. I went down the domestic route as I thought I had 3 hours to clear immigration in Bangkok. Big mistake! I made it by the skin of my teeth onto my connection to Dubai but I know that many others didn't make their connections. Should Thai have held up a domestic flight because people were delayed clearing Immigration?? Be warned it could happen to you.