Dear Jarl Ulfric Stormcloak,
You may remember that we met in Helgen. I was the Dunmer that was about to have his head cut off when the Dragon attacked. I also helped your mate Ralof escape to his sister's house in Riverwood.
As per Ralof's suggestion, I headed to Windhelm to assist in the war on your behalf. However, when I arrived, the first thing I noticed was a couple of your Nord citizens harassing and threatening a fellow Dunmer. Now, I'm sure racial tensions are high and all that, but I think it can safely be said that threatening a woman with implied rape should be a matter for the guards, regardless of skin color or shape of one's ears.
Upon further investigation, I discovered that this sort of behavior is not only tolerated, it's quite common. Furthermore, I discovered that, rather than being integrated into the city, the Dunmer in your hold are forced to live in a slum, a dirty back alley with serious hygiene concerns. The "Grey Quarter."
You understand then, why my decision to aid in your little rebellion was suddenly called into question. If this is the sort of behavior you allow to occur in your own city, what sort of treatment can my fellow mer expect should you become High King?
Do you deny that your treatment of Nords has always been preferential? Can you account for the rumors your follower spread that you intend to exile all non-humans from Skyrim as soon as you take the throne? Can you give one reason why anyone but a Bigoted Nord would take up arms under your banner?
Perhaps you take offense at my tone. I certainly hope so, as I take offense at your actions and inaction regarding my people living on your very doorstep.
If you want me, or any Mer, Argonian, or Khajiit, to considered doing anything other than taking up arms for the Imperial cause, I suggest you turn your treatment of non-humans around.
Oh, I forgot to mention. I am Dragonborn. I have been proclaimed Ysgramor, Dragon of the North, by the Greybeards. I also have the allegiance and service of all remaining Blades.
Consider that in your calculations.
-Monte Cristo, Dragonborn.
Not so serious one:
Dear Madanach,
Remember when I helped you escape from prison? Yeah, do you think maybe you could get your Forsworn to stop attacking me?
All it's doing is killing them and hindering me. You'll save me some time and a lot of your followers get to live. Also, if this goes on, I may have to come to... other arrangements.
I trust I make myself clear.
-K'Reegar, Listener of the Black Hand.