I hope that they dont convey their greetings on the mic, and they dont have to announce to everyone that they have sent a greetings card.

Dont know dude but in the parties I have been the host greets you personally and he doesnt say it on the mic, "Hi How Ya Doin"

Anyways its up to you. I have made my message loud and clear on the forum and for personal greetings I tend to use email, greetings card etc. To me thats much more appropriate and its the norm.