Letters to the Editor

In Magazines, there are quite often letters to the editor. This trope is so common in magazines that only unusual examples are listed here. May be a Strongly Worded Letter.

If fictional characters answer the mail, that's Fourth Wall Mail Slot.

Examples of Letters to the Editor include:

Notable Magazine/Newspaper Examples

Marvel UK commonly has the letters answered by a character.
Disgusted of Tunbridge Wells.
Yes, Virginia was a response to an actual letter to the editor from an 8-year-old girl.
2000 AD has always had its letters answered by Tharg The Mighty, except for one time in the The Nineties where characters from Vector 13 took it over while Tharg took a leave of absence.
In Mad Magazine's "Letters and Tomatoes Dept", letters were typically answered in a snide and insulting manner. They also published many letters that mocked the magazine creatively.

Other Media

Comedy

Russell Brand exploited The Sun's letters page for comedy gold in this act.

Comics

Alan Moore's 1963 would have a fictional Letters to the Editor page, parodying the columns Stan Lee would put out for Marvel in the The Sixties.
Letters to the The Sensational She Hulk were answered by the titular character or one of her supporting cast.
Ambush Bug answered his own letters, and in his first issue was puzzled that he had to wait months for feedback from the reader who had just finished the book.
Most American comic books had letter columns until the late '80s.
- a few independent comics still feature them.

Literature

Parodied by the National Lampoon: Its Letters section had funny made-up letters, often supposedly from celebrities.
P. G. Wodehouse dealt with this in the "A Letter to the Editor" chapter of Louder and Funnier, in which he includes his poem, "Dear Sir: I take issue with Walter S. Swisher."
Famously, pornographic magazines like Penthouse had letters pages where people wrote about their sexual experiences; most were made-up by the magazine's writers.

Live Action TV

Monty Python's Flying Circus regularly parodies this (and Points of View) with letters written to newspapers that read as if the writers were on drugs or crazy.
In the A Bit of Fry and Laurie sketch "Slightly Mad", the only way Arthur Meddlycott can convince his psychiatrist that he's insane is by revealing that he writes letters to newspapers — and apparently has them all memorized.