Nailed or Mailed?

...it's hard for me to think those words without hearing my son saying them as 7 syllables with emphasis. He seems to have picked up some things about Martin Luther but I don't think he understands the question that interests me here. Did Martin Luther nail his 95 theses to the church door or send them in the post? A blog post here handles it fairly well. I think Melancthon is reliable.