Something wrong ??

Got an envelope with some nice stamps in it as a birthday gift. I am a member by ANSC and also a member of the Birthday club there. The envelope was in a plastic bag with a special sticker on it RM it says with the name of a department of our TPG Post. Have no idea what that is about. There was no damage or so so why they pick it out of the normal mail ???? Show you the package and also the unpacked letter, as you see one stamp is a bit folded and not collectable any more I think. If any one knows what happens??? Let me know.