Dear Twilight Sparkle:
HOLY MOTHER OF ME your dreams are so fucking hardcore!
I'm terribly sorry, Twilight, but I'm going to have to drug you. We really need your dreams.
Your soon-to-make-millions-off-the-porn-industry former teacher, Princess Celestia.
P.S.: Say hi to the olden pony and the headless horse for me.
Dear Scootaloo:
Congratulations on obtaining a new older sister figure. Just make sure not to fuck up her flying lessons, or she might decide to take you on her take-your-sister-to-work-day tour.
Of course, it might not be so bad. We hear that the Rainbow Factory really likes flightless pegasi for some reason.
Thy new favorite princess, Luna.
Dear Rarity:
Seriously?! Using your own sister as slave labor?! That's low, even for you. Spike may be swayed by your charms, but I know better.
Your disgruntled un-sister, Sweetie Belle.
Dear Olden Pony:
How do you expect me to find your stupid horseshoe? I don't even have a head. And besides, if it's as rusty as you say it is, why don't you just buy a shiny new one?
Sincerely, the headless horse.