Tumblr just announced a new private messaging feature called Fan Mail. It’s a more personal means that’s not email, which requires you to know your favorite blogger’s email address (do you?) or the handwritten form of the 20th century, snail mail. That leaves two social network-y means of contact: Facebook private messages and Twitter direct messages. Depending on the blogger’s comfort level, however, they may not make Facebook messages on profile pages an option. Similarly, not every blogger follows fans back on Twitter.