if you mean private messaging im not sure thats possible, any posts you make to your timeline will show on theirs though if they havent blocked your posts from appearing in their feed (that is teh problem alot of pages get from spamming to many posts in a short amount of time, people may not "unlike" but can hide all your posts from their feed). But as for private inboxing fans i dont think tht is possible unless you do it one at a time i guess