This letter lets someone know you miss them even though you're far apart.
1234, Main Street
Boston, MA 02123
07 April, 2005
<Recipient Address Goes Here>
I just wanted to send you a note to let you know how often you are in my thoughts. Although the distance between us makes it hard to keep in touch sometimes, you remain one of my closest friends. I certainly miss our chats and being able to get together more often. I know, though, that ours is a special friendship, which will endure any distance, no matter how great.
<news, gossip, etc.>
I hope this letter finds you well, dear friend. Please remember how very much you are loved and missed.
encl: <List of enclosed items goes here>