Irrevocable Message

A story in which a character, often in a fit of anger, sends some form of communique that they then want to take back, only it's too late! Wacky hijinks ensue!

Usually, if it doesn't get taken back, the character's in danger of losing their job or their relationship. It almost always ends in one of two ways: they manage to get it back at the last second, usually through a Zany Scheme, or the person it was intended for gets it, but doesn't mind.

If you're in a drama, however, beware: dramatic media are not as forgiving with this trope as comedic media, as an Irrevocable Message in dramatic media tends to result in some kind of tragedy or other serious loss.

Examples of Irrevocable Message include:

Anime and Manga

In Bakuman｡, Miura, during a heated argument with the main characters over whether they should do a gag manga, says that if Mashiro won't do it, Takagi should find someone else to draw for him. He quickly realizes that he's wrong, and goes to apologize, but not before a shipment of gag mangas with his notes on how they do humor arrives at Mashiro and Takagi's office. The two are initially offended at how persistent he is, but realize that he wouldn't have sent it after the argument, and come to understand how serious he is about gag mangas by the time he shows up to apologize, desperately hoping they haven't gotten the package yet.

Film

The entire premise of the film Overnight Delivery is set around this device. The protagonist, Wyatt Trips, sends a nasty break-up message to his girlfriend when he believes she cheated on him, only to discover later that he was mistaken. Only it turns out that he wasn't mistaken.
Not quite the same, but: The main character in Road Trip believes that his dumb friend sent a video of him cheating on his girlfriend to her. The movie is about him going to try and get it back.
- The sequel Euro Trip had the main character offending his chat buddy Mieke when she said she loved him, thinking it was a boy's name. When he finds out it's a girl's name, she's already blocked him. Hilarity Ensues.
An Irrevocable Message kickstarts the plot of Atonement, though it's also due to Briony spontaneously deciding to read the letter that was never meant for her and then show it to her mother.
In My Best Friend's Wedding, Julianne (played by Julia Roberts) sends an e-mail from Michael's account in an attempt to cause trouble between Michael and his fiancee.
Memento runs almost entirely on this trope. Lenny sends himself messages which—5 seconds later—are too late to take back, because he won't remember why he wrote them (and believes his own handwriting implicitly). This drives the plot of the color portion of the movie, where he convinces himself to tattoo Teddy's license number on his thigh. Then again, he actually does mean what he's writing when he writes it - but given his condition, he's a new person every 15 minutes, constantly having to contend with whatever the "previous" person had in mind.
Never Put It In Writing depends entirely on this trope, and the attempts by the hero (Pat Boone) to intercept a letter from the Irish and British postal services before it reaches its intended recipient.

Literature

Douglas Adams's book Dirk Gently's Holistic Detective Agency subverts this a little, when a ghost tests Richard MacDuff's suggestibility by subconsciously pushing him to go to extraordinary lengths to erase a fairly inoffensive message from his girlfriend's answering machine.
Back in pre-email days, writer Isaac Asimov once detailed his method for avoiding sending one of these: write up the nastiest, most vitriol-filled screed your pen can spill forth, put it in an envelope, seal, address and even stamp the envelope.. then rip the whole thing to shreds and write something more moderate.
In Lois McMaster Bujold's Memory, Miles Vorkosigan composes a report to his superiors completely obscuring the fact that the rescuee was injured by human, not mechanical, error on Miles' part. Further complicated by the fact that Miles decides to come clean and claim that he omitted the detail for the sake of security, but then changes his mind back when he thinks his boss is about to offer him another mission. His boss already knew what had really happened, and was offering Miles a chance to redeem himself. He failed the test.
The interstellar explorers in James Tiptree's story A Momentary Taste Of Being have only enough resources to send a single message back home to tell a followup colony fleet whether or not it's safe to follow. The outcome is summarized in this FilkSong.
In Atonement, Robbie writes two letters to Cecilia apologizing for his earlier behavior. One includes a sentence spoilered for reasons of taste: "In my dreams I kiss your sweet wet cunt all day long." Guess which one he accidentally sends.
In the Sherlock Holmes short story The Adventure of the Second Stain, an unnamed political figure writes a strongly worded letter to the British Government - so strongly worded that it could potentially cause an international incident. He then regrets writing it after it gets sent out. In a trope inversion, the recipients were very sympathetic and are welling to smooth everything over. Holmes is only tasked with tracking down the letter after it was stolen, and presumably on its way to to less sympathetic governments.

Live Action TV

The Laverne and Shirley two-part episode "The Bardwell Caper" involved the two characters retrieving a nasty letter they had written to their boss.
The Three's Company episode "Out on a Limb" involved Jack Tripper trying to retrieve a scathing letter sent to a food critic.
In the Seinfeld episode "The Phone Message", George Costanza leaves nasty messages on his latest girlfriend's answering machine then, with Jerry's help, tries to switch the tapes before she hears the messages.
- Subverted as his girlfriend had already heard them and thought it was merely George playing a hilarious joke
- In "The Sniffing Accountant," Jerry suspects his accountant's sniffing as a sign of drug use and, fearing for his income, writes a scathing letter ending their association. When an unrelated character also sniffs around Jerry and reveals that it's an allergic reaction to his mohair sweater, Jerry tries to stop Newman from mailing the letter. It's subverted when Newman fails to deliver the letter after getting handsy with a woman. To top it off, Jerry later finds out the accountant is going bankrupt and wishes the letter had made it.
Rachel's drunken "I'm over you" message on Ross's answering machine in Friends in "The One Where Ross Finds Out."
- Monica did this in "The One Where No One's Ready"; after finding an old message from ex-boyfriend Richard (Tom Selleck) on her answering machine, she calls him and leaves a message on his machine, which she immediately regrets and decides must be erased. Cue wacky hijinks.
The Are You Being Served? episode "Goodbye Mr Grainger", which had the elderly and depressed Mr. Grainger resigning in a rather unpleasant letter insulting everyone on the store. Fortunately, he snapped out of his depression and the letter was retrieved before it got to the boss.
Ellen coming out over a loudspeaker.
The Jonathan Creek episode "The Problem At Gallows' Gate" featured an answering machine message filled with threats towards the victim from one of the suspects. It was removed from the machine by the murderer, who wanted all the evidence to point to another suspect. Then the blank tape was stolen by the suspect who left the message, since he didn't know this. Then the next blank tape was stolen by the other suspect, who thought he could use the message to clear his name.
The Mary Tyler Moore Show had an episode where Mary has to stay up all night at her apartment updating the newsroom's obituary file. The next morning, she's almost finished when Rhoda comes in and starts cracking jokes about the last entries in the file, including some tasteless jokes about William Williams, who at 110 is the single oldest living person in Minneapolis. Mary, in a tired, giggling mood, types them into the file. Guess which famous person happens to die that very day and whose file is read aloud live on the 6 O'Clock News before Mary can correct it?
In The West Wing, Toby and Will have to write a speech for President Bartlet announcing his choice of "Bingo Bob" Russell as the new Vice-President, even though nobody in the White House (not even Bartlet) really wanted him. Frustrated at having to come up with something nice to say, Toby and Will start dictating a rant on how much they all despise him and how useless a Vice President is. Of course, it accidentally winds up on the teleprompter. Fortunately, the President is able to improvise a much kinder speech. Unfortunately, "Bingo Bob" can see everything on that teleprompter. Fortunately, he thinks it's hilarious.
In an Everybody Loves Raymond episode appropriately named "The Letter", Debra wrote Marie a letter in which she told her mother-in-law exactly what she thought of her. Ray thought this was a very bad idea and attempted to intercept the letter. He failed and was ultimately forced to sit in his parents' house and listen as Frank read the letter out loud. At one point, Frank said "Is this a petition? Where do I sign?"
There's an episode of Spaced in which Tim frantically tries to retrieve a caricatured portrait of his boss that has accidentally been slipped into a portfolio that his boss requested. While Tim is making his getaway after retrieving the picture, the boss gets his hands on it but it is screwed into a ball at this point, and thankfully the boss doesn't open it up but just throws it away. He gets it because the boss' assistant, who had a crush on Tim, went through the portfolio and removed it. And also takes out the less insulting but no more appropriate picture of her, which he'd forgotten about.
In an episode of The Dick Van Dyke Show the writers accidentally turn in a script which has all their sarcastic comments about Alan Brady not blacked out, and they attempt to retrieve the script before he reads it.
In one episode of M*A*S*H, Major Winchester gets the news that his sister is marrying - an Italian. He completely loses perspective, sending a series of racist, elitist and cruel letters until he learns that the wedding was called off by the groom's family. At this he sends a contrite telegram; his sister's reaction was never shown.
In an early episode of Jesse, Jesse drunkenly pens a letter to her boyfriend after their first date, containing the one phrase a girl should never say to a boy after a first date: "I want to have your baby". She attempts to get it back and Hilarity Ensues, culminating with her getting her hand stuck in the mail slot of his front door.
One of the "lost episodes" of The Honeymooners has Ralph firing off one of these to his boss after (mistakenly) coming to believe that he's about to be laid off anyway. No sooner has he dropped it in the mailbox than he discovers that he's actually in line for a promotion.
The L Word has one storyline where Bette decides she wants sole custody of Angelica, largely due to the fact that both she and the baby are biracial (and Tina and her new beau are both white). She reconsiders, but by then it's too late, and Tina has just received Joyce's fax. Bette then kidnaps Angelica, but the bub is later returned and Tina doesn't press charges.
Double-subverted in the Taxi episode "Bobby and the Critic". A powerful Smug Snake of a theater critic raises Bobby's ire, causing him to fire off an angry letter to the critic's newspaper. Bobby's letter gets published and he's sure he's kissed his career goodbye, but to his astonishment the critic seems to have taken it in stride and even shows Bobby a glowing review he's written for his most recent performance...only to turn around and get his revenge by tearing it to pieces right in front of Bobby's eyes.
On Top Gear, Season 13, Richard Hammond and James May used a Porsche Panamera to pursue an mailed envelope from the extreme south of Britain to the extreme north. May's writeup of the event for the Top Gear website claimed that the envelope contained a compromising photo of the two of them which they were trying to retrieve. They failed.
Herman's Head. Herman writes in a workplace assessment that his boss Mr Bracken is a bit gruff, then panics when he hears another boss lost his job over such an assessment. After various shenanigans to intercept the message he fails, but the CEO is surprised at all this—after all Mr Bracken is a bit gruff. The last boss was fired simply because he was incompetent.
On an episode of Coupling, Patrick broke up with a girl he was with through her answering machine, but when she suggests a threesome, he hurriedly tries to correct it with another message, claiming that his flatmate Ivan likes to pretend to be him and dump his girlfriends. This is ruined when Jane and Steve interrupt him without realising he's on the phone. He then continues the message, claiming to be Ivan, but Linda interrupts him and gets her voice on the message before he can hang up. Luckily, she sends him to her apartment, allowing him to change the tape.
- A funnier one from the first episode where Steve calls Jane to break up with her. He is cut off by the messagebank being full just after saying "a man would have to be insane not to want to spend the rest of his life with you."
The Thick of It has an episode on this trope. "I promise that I will never call an eight-year-old girl a cunt again."
Played for both laughs and drama in the Zoey 101 hour-long movie "Spring Break-Up". Chase, who has been harboring a years-long crush on best friend Zoey, accidentally sends her a text message that reveals his true feelings. He gets it back in time to delete the message, but ends up losing Zoey's friendship in the process. After (mostly) explaining himself, he regains her friendship and gets the courage to tell her how he really feels. Unfortunately, the text message he sends never gets read, as Zoey's phone is forgotten and falls into a fountain, effectively killing both the message and the phone.
Supernatural did a bizarre variation on this problem: after their single biggest falling-out in the show, Dean left Sam a mending-fences type voicemail which included an apology. The angel Zachariah monkeyed with it, and the message Sam got was one of hate and repudiation with an implied death threat. Sam then gave up and finished his Well-Intentioned Extremist slippery Slope trip. So far as we know, seasons later they still don't know this happened, because they are bad at communicating, and Sam still thinks Dean gave up on him.

Newspaper Comics

In one Dilbert strip, Dilbert sends voice mails to his boss in the middle of the night to create a reputation as a hard worker. Half asleep, he mutters that he's "sitting here in my underwear thinking about you". When he tries to delete the message, he instead sends it to the entire office.
- One series had Tina the Tech Writer accidentally send a steamy e-mail intended for her boyfriend to everyone in the office. Catbert decided not to punish her if she rubbed his furry belly with the Does This Remind You of Anything? implication that... well, he might have asked her to do something different if he were human.

Theater

Shakespeare's Richard III plays with this one by having Richard let King Edward think he's failed to countermand his impulsive order to execute George—thus conveniently allowing Richard himself (who's had George killed behind Edward's back) to escape suspicion. Ian McKellen's film version shows Richard burning George's pardon with a Zippo lighter.
Played straight, however, in King Lear, where the villain Edmund, after being mortally wounded, attempts to call off his order for Cordelia to be executed, but it's too late.
This is actually a trope of classical tragedy. It occurs in the Ancient Greek play Antigone, in which the antagonist Creon tries to save his niece, the title character, from being buried alive on his own orders, but finds she has already hanged herself. In turn her fiance, Creon's son, stabs himself, leading Creon's wife to commit suicide as well.

Web Animation

On Homestar Runner, in an edition of "Marzipan's Answering Machine", Homestar misinterprets a voicemail message from his girlfriend telling him to "go to Richway and pick up some Hefty bags" as "go away and pick up sticks". He leaves a break up message, then realizes his error and tries to rewind the tape. Since he's on the other end of the phone, his method was just to make rewinding noises with his mouth. He then dashes over and replaces the answering machine tape with his own tape full of fake messages featuring clumsy imitations of the other characters (including himself, oddly enough).

Western Animation

Helga's confession message to Arnold on the Sunset Arms' answering machine in Hey Arnold!!, "Helga Blabs It All".
The Flintstones did this once, where Fred sent an angry letter to his boss over a misunderstanding.
The Simpsons had an episode where a dying Mr. Burns is saved by Bart's rare blood and thanks the family with only a card, prompting Homer's angry composition of an insulting letter. Despite coming to his senses, Bart sends the letter to Mr. Burns anyway, and part of the episode deals with attempts to retrieve or destroy it by flooding (along with all the other letters in the mailbox). The gambit fails, and Homer is fired.

Homer: (in unnecessary fake voice) Hello, my name is Mr. Burns. I believe you have a letter for me.
Mail Guy: Ok Mr. Burns, and what's your first name?
Homer: (still in fake voice) I don't know.

- In a (much) later episode, Bart's attempt at mail-tampering results in several people gratefully retrieving their ill-considered messages.
In a similar vein, Rabbit spends one episode of Winnie the Pooh trying to stop his friends from opening a treasure chest before they find out it's full of stones (which he put there to make them lose interest in looking for treasures - It Makes Sense in Context). Hilarity Ensues, as he must do this without them finding out he fooled them into thinking it was a real treasure chest.
- Then it turns out they all needed the rocks for various reasons.
House of Mouse had Mickey, trying to figure out how to work his new fax machine, sending a love letter to Minnie and an insulting note to Mortimer through it. When he discovers that Mortimer got the love letter, he urgently tries to get the fax Minnie received away from her. At the end, it turns out that the fax Minnie was carrying was written by Daisy and was wholly unrelated to anything Mickey wrote; the insulting letter actually wound up in the hands of Roy Disney.
Phineas and Ferb- An eregrious "evil scheme" of Doof's was to hoist a giant magnet over his new girlfriend's house in order to erase some long, rambling messages during their "relationship bump".
- In another episode, Candice desperately attempts to keep Jeremy from checking his phone before he sees the derp-tastic pictures she accidently sent him.

Real Life

How many times have you sent an e-mail/IM/text message that you wish you didn't? Truth in Television, with the advent of really quick and convenient ways to send messages, which can be composed and sent before the sender comes to his or her senses.
Drunken texts are common enough and come in so many varieties that a Facebook group exists in their honour.
A popular Bash.org quote had a man in IRC accidentally message his girlfriend's mother an explicit description of what he wanted to do to the girlfriend. Not done in anger, but he can't take it back.
- These two bash quotes involve the Irrevocable Message getting posted to bash itself; the latter includes a promise not to post it which is then given the Exact Words treatment by asking a friend to post it.
- Google Mail recently added an optional feature where you can unsend messages up to 5 seconds after pressing send, specifically for this sort of thing.
  - You can also have it ask you math questions before it will send mail during set hours, to prevent drunken emails.
There was a young woman, in 2007, whose boyfriend went on a two-week holiday to Europe. He informed her of this and even called her the night before to say goodbye. Apparently she caught the Idiot Ball during the build-up to the trip itself, because she spent the next thirteen days calling and emailing him, trying to find out where he was and why he wasn't answering. These emails and voice messages went from just trying to get in touch with him, to livid, to pleading, and then back to livid. The day before he got back, she dropped off a box of his things from his mother's house - and finally found out why he hadn't been responding. She sent one last email, begging him not to read or listen to any of the other messages she'd sent during the trip. He read the emails and listened to the messages. They're no longer together. The full story is over here: https://web.archive.org/web/20130908042436/http://jdsmanstories.net/?p=566
Supposedly Queen Elizabeth I didn't mean the death warrant she had signed for Mary, Queen of Scots actually to be enacted but the Privy Council decided to carry out the execution before she could change her mind. When she found out she was not pleased (though it has been suggested that this was an act).