Dear Sir
Please don’t.
Asympotically Fat, Esq., East Cheam
Dear Sir or Madam:
It is sexist to assume that only men write open letters. I demand a public apology for your shameful misogyny and a $1,000 gift card to Scores.
East Cheam? I get the reference, but where does East Cheam end and West Sutton begin? There’s not enough of Cheam to have sides. 
An Open Letter to People Who Write Open Letters
Just so you know, the inside of the envelope flap is covered with an adhesive. Just place your letter inside the envelope, moisten the flap, and press the flap to the main part of the envelope.
Which reminds, why, exactly, did so elegant a thing as sealing wax ever fall out of favor? I think the time has come to talk about that. Also, cabbages.
And kings!
What’s that? No kings? Well, all right, I guess.
Definitely shoes and ships, though.
“The Vulture and the Husbandman” – Parody of “The Walrus and the Carpenter”
Undergraduates are ploughed (flunked) on Viva-Voce (oral examination) day.
Excerpt:
I think it was that magic dragon named Puff. Somehow he used all the sealing wax.
Always fancied that stuff.
If you’re gonna write me a letter, good sir, at least offer tips on how to get laid.
Dear Sir, Madam or X
Your “pitting”, which is not worthy of that label, contains no information about your gripe, nor context about what constituted the final drop that caused your undersized beaker to overflow. The open letter is a perfectly cromulent genre and, even if slightly overused, makes a nice change from the plain old opinion piece.
sincerely captain Johnson, Mrs.
…in a white wine sauce with shallots, mushrooms and garlic.
I am currently composing an open letter on the merits of open access, open carry, open marriage, open container laws and open mic nights, which promises to open a can of whoop-ass on the opposition.
Cisgendered swine!!
I once cut myself with a letter opener so I don’t like them.
Lower your standards. Repeat as necessary.
Open letter? Like “U” or “C” ?
To Whomsoeversomuch It May Concern,
As you can see, my grammar is better than yours. I use awkward words which are no longer in dictionaries ever since Those Sorts (Allsorts (Licquoririce)) began writing them, or writing to them, or etc. and et al. and Anon. I also use a better (that is, which is to say, more incomprehensible and more verbose) class of spelling, which reflects the language before Noah Webster and Samuel Johnson got their hands upon it. I also have a point, which I am getting to in a flowery and therefore inoffensive (until you think about it) manner, to hide my deeply reactionary, revisionist, retrograde, and revolting views, but I hardly know why I bother, as I am writing to the Daily Mail and/or FOX News, which publishes the truly idiotic in twenty-point type.
I remain, as always, sincerely, forever, and ever, and anon, and amen, and, respectfully, dearly, fragrantly,
Disgusted,
Tumbridge Wells
PS: A file format which is not used nearly often enough.
PPS: What comes after one of those files.
PPPS: Be very, very quiet!
PPPPS: I am the Village Green Preservation Society
Also, to tack this on, here, at the end, do you know where to find some more green ink? I have a mathematics paper to publish.
Whattayou got against open letters?
An unopened letter remains unsuccessful until it is opened.
What do you have against success?
Why do you hate America?
Dear God:
Da fuq?
Yours,
Me.