Dear Ada,
I will be home shortly. Frodo finally decided to wake up after Merry and Pippin used his bed as a trampoline, so Aragorn has been coronated*. I should be back in a few weeks.
Your loving son,
Legolas

Dear Legolas,
Things are growing rather strange here in Mirkwood. For one thing, two of the red-headed boys are running wild, and keep setting off fireworks everywhere. Rudolph has become most upset. The rest of the invaders have taken over a large area of the palace. I sent in some of the army to bodily remove the invaders, but they were again attacked by the sticks.
In addition to all this, the Trio seem to have broken out of Orthanc and are back in Mirkwood. Upon seeing the Nazgul, the boy with the scar summoned a great silver stag, which attacked the Nazgul and then began roaming the corridors. No-one seems to be able to get rid of it.
Forgive me; I must go. I just heard another explosion.
Your loving father,
Thranduil

Dear Ada,
On second thoughts, I will in fact be staying in Gondor for a few more months until Aragorn and Arwen's wedding.
Your loving son,
Legolas

Dear Legolas,
Well, both the invaders and the Trio have gone. They managed to kill each other off in an epic rap battle yesterday. Sadly, the two red-headed demon boys appear to have bequeathed their entire supply of fireworks to the servants, so things are still a little upset here.
I must go; I think your room just caught fire.
Your loving father,
Thranduil

Four Years Later

Dear Middle Earth,
The power of the Three Rings is ended. Therefore myself, Mithrandir, Galadriel and Celeborn are all sailing over the sea to Valinor. Frodo and Bilbo are coming with us, too.
Oh dear. That was supposed to be a secret.
Anyway, this is my last farewell to Middle Earth and all my dear friends who live there. And Thranduil. Goodbye, all of you.
And, Elladan, Elrohir, if you break that antique vase from Beleriand that lives in my study in Rivendell, I will know. Even if I am hundreds of miles over the sea, I will know.
Cordially,
Elrond Halfelven.
P.S. All the postmen appear to be leaving middle earth as well, so I do hope that this letter reaches you all in time.

*My spellchecker doesn't think "coronated" is a word, but ah well. It also thought "spellchecker" wasn't a word, sooo…