You know, i never really thought of that. I send multiple Christ-mass cards to all my freinds and family, even my Muslim freinds. Most of them just thank me for the gesture.
I, and my family celebrate Christmas a little bit different. We do not throw parties or exchange gifts (well sometimes). We focus only on the true meaning of Christmas wich is the birth of Christ. For most Christmas is nothing more than presents and parties, and some i speek with just believe in Santa Claus or Saint Nicholas. I will not let my family focus or believe in a fat guy who sqeezes his body through a chimmeny giving gifts. My Nonna (Grandmother) used to say "That is nothing short of idol worship" She only focused on the birth of Christ.
Here is what my family does
1.)Christmas eve, service at church- 3 Hours
2.)Christmas day, Service at church- 5 hours
3.)Christmas night, Personal and family prayer-approx 6 hours
basicly all prayer, my mother will decorate some but i put up no tree. I wake my son up and pray with him, read the Bible about Christs birth and them we go to the food drive to feed the poor and needy. I give my son 4 gifts and he has to pick 1 gift to give a child that does not get the chance to have one. Last year he gave all of his to a Muslim family i am freinds with that had fallen on rough financial times and they just happen to have 4 boys.
I think we as Christians have forgotten what Christmas means. We should not focus on the best gifts idol worship or besting each other with monitary items.
God bless, and for the Christmas card thing...just accept them no one is out to insult you by this, i actually just bought Happy new Year cards this year for my Muslim friends.