Needing to send a Christmas card to a family in Spain.

How should I address the envelope? In the USA, we might write:
Mr and Mrs John Smith and Family. The 2 last names confuse me.

Thanks for the help!

if its a family you know, you can just print their last names as familia Smith Jones. In Spain we use the two last names one father one mother ::) given credit to the Mom!

if its one person, you can write the name John Smith Jones y familia. No need to put Mr or Mrs unless you hardly know them but for Christmas card, then you know them ::)
Merry Christmas
You can say Feliz Navidad y Prospero Anho Nuevo (need to use the N word in Spanish my keyboard wont let me)
Cheers

Thanks Pedmar and Joyeux Noel et Bonne Annee to you and your family!

One more question is the man's name first or second or does it matter?

I believe the man's name is first.

For example..Sr Juan Rodriguez Alvarez and family

merci vous de mémé jacmon.
yes you got it above, the man goes first lol!

Thank you everyone! and Merry Christmas!

Thank you everyone! and Merry Christmas!