Habitat(s): Majority
It is said that if one were to write a diary or journal while
within the Backrooms, once they are deceased, a mysterious entity called "The Mail Carrier" would retrieve their memoir and deliver it to the victim's close ones who live in the Frontrooms.

A picture of The Mail Carrier after it delivered "Mail" in the Frontrooms.
All of the information below is confirmed by a book that The Mail Carrier lost at an unknown point in time. A M.E.G officer found this book in Level 11, containing the conversation between The Mail Carrier and Entity 140, also known as Blanche.
Description:
The Mail Carrier is an entity that delivers mail to people in the Frontrooms. Unlike the mail carriers in the Frontrooms, the only type of "mail" it handles are the diaries and journals of those who have unfortunately succumbed to the horrors of the Backrooms. The Mail Carrier is currently working with Blanche. The details of their connection is documented in The Contract.
Behaviors:
There are very few reports on how The Mail Carrier behaves, but it is well known that it is somewhat shy, and is unwilling to show itself to wanderers.
A certain group that call themselves the Informants have claimed to be able to have short conversations with this entity using unorthodox methods.
Biology:
The Mail Carrier's appearance differs when in the Backrooms and in the Frontrooms.
Within the Backrooms:
All descriptions of The Mail Carrier's appearance within the Backroooms are different. There have been multiple sights of this entity being an animal, human, or even an object. Despite this, all of the wanderers who have claimed to see it had one detail in common—its tall, slim figure approximately 1.5 times the height of the average human.
In the Frontrooms:
The Mail Carrier’s appearance in the Frontrooms is similar to its appearance in the Backrooms, albeit more humanoid. However, it maintains its height and its long, slender legs. It wears a butler outfit and a top hat. It carries a brown leather briefcase, holding it protectively as it strides across the road. It is believed that the briefcase possesses fourth-dimensional properties, making it easier for the entity to hold a large number of diaries.
Discovery:
The Mail Carrier was first seen by a wanderer in Level 0 named Alice Morningstar, who picked up Object 96.1 after The Mail Carrier dropped it. Alice wasn't familiar with this entity, nor could she hold a conversation with it due to it dissolving within the shadows as soon as she picked the book up.
Casualties caused by The Mail Carrier:
The Mail Carrier isn't hostile to wanderers, but it can provoke indirect negative effects on those who are unlucky enough to experience them. Some of them are:
・Feeling of paranoia when stalked by The Mail Carrier for holding onto a lost diary.
・Disappearing within a week after reading The Mail (Lost diaries mailed by The Mail Carrier) in the Frontrooms.
・Odd behaviors when reading and subsequent to reading The Mail given by the entity.
Sightings:
Because of all the places The Mail Carrier goes to collect lost diaries, this entity is believed to possess the ability to traverse all levels in the Backrooms. How it does this, however, is unknown.
There is one level in particular where it lingers for a majority of the time. This level is Level 906, also known as The Cygnus Archive.
There have been multiple sightings of The Mail Carrier within "The Panicking State" of Level 186. It is theorized that it uses this level as a rest point.
There is one level that The Mail Carrier never enters— Level Fun. This entity cannot retrieve lost diaries in Level Fun, as it keeps away from partygoers at all times. The reason appears to be connected with The Mail Carrier’s master, documented in The Contract.
The Mail Carrier can be seen in the Backrooms retrieving lost diaries. When a wanderer holds onto a lost diary, this entity may stalk them for extended periods of time, leading weak-minded wanderers to suffer symptoms of paranoia. When in this situation, one of three outcomes will happen.
・The Mail Carrier will eventually lose interest in the lost diary and leave it in the hands of the wanderer.
・ If the diary is placed on the floor and left behind, The Mail Carrier can and will retrieve it.
・ In rare cases, it will be stolen while one is asleep. In such cases, the wanderer will find a sticky note on their belongings that says "Sorry."
One can also see The Mail Carrier in the Frontrooms if they happen to be nearby when it delivers mail to people. One can sometimes catch glimpses of The Mail Carrier retreating in long, smooth strides if they were to open their front door fast enough when receiving mail from it.
The "Mail":
The people who receive mail from The Mail Carrier will always lock themselves in their rooms and proceed to read the mail without stopping. They will not do anything except read the mail until it is finished. One person kept reading for 4 days straight, which led to severe sleep deprivation and dehydration.
Any attempt to enter the closed room will result in the person screaming at them, telling them to not come in. If one were to barge into the room regardless, they would find that the person has disappeared. Trying to make contact with people that have disappeared in this way has not yielded any results.
After they have finished reading the mail, they will immediately erase the mail by any means necessary, usually by burning it. Since the room is closed, smoke inhalation may cause the person to develop chronic obstructive pulmonary disease and asthma. When burning it isn't an option, they will rip the mail into shreds using tools, teeth, bare hands, and other methods. Once shredded, they will proceed to swallow the remnants of the mail.
When the person comes out of the room, they will have no recollection of most of these actions. Even when confronted with solid proof, they will deny it and say that they only remember reading the diary that was mailed to them, claiming to not know its current whereabouts.
Most people who have finished reading the mail will go missing in a week. This has been proven to be avoidable. If a person who has read the mail were to be watched for a week, they will be safe from disappearance. This is confirmed by The Mail Carrier itself in The Contract.
Motives/Objectives:
Though the objective of The Mail Carrier is not clear, there are many theories as to why it goes out of its way to collect and return the lost diaries.
Here are some of the most popular theories.
・The Mail Carrier was once a wanderer itself, which is why some of the words in its book (gifted by Blanche) included English. Following its death, it wanted more information about the Backrooms known to people in the Frontrooms to prevent more people ending up in there.
・The Mail Carrier feels sympathy for those who had to endure the despair caused by the Backrooms, which only ends in an uneventful, forgotten death. As a result, this entity feels obligated to give these wanderers’ stories to those they care about.
・It is an order by The Mail Carrier's master, with their objective remaining unknown. This theory is most likely incorrect else The Mail Carrier wouldn't have accepted the conditions of the contract with Blanche.
There are also theories that The Mail Carrier has malicious intent in its actions, the most popular one being "The Cycle Theory".
The Cycle Theory:
This theorizes The Mail Carrier understands the bond between those who already know the victim is much stronger than the bond of strangers. By mailing the diary to the unfortunate wanderer's close ones, it urges them to enter the Backrooms for some unknown reason. This theory is evidenced by the disappearances of those who recently received mail from The Mail Carrier. Nobody knows if this entity has tampered with the diaries, but it is most likely, hence the abnormal things that happen when reading one.
Possible Masters?:
There have been many guesses as to who it serves, the top 3 being:
The Keymaster
Hubris
Prometheus
Because of The Mail Carrier's actions, its master will most likely be somewhat interested in either the wanderers or their tales. It may also be best to think that the master of The Mail Carrier is not hostile towards wanderers (unless The Cycle Theory is true). If one were to think about it, The Mail Carrier has the ability to travel through all but one level, so it could be an easy task to dominate all of the Backrooms. At the same time, The Mail Carrier's master may not have full control over it, hence the sticky notes that it sometimes gives to people, proving that this entity has some sort of autonomy.
Stop filling their heads with lies…
Do's:
- Ignore it. It minds its own business and is shy, but polite when approached.
- Help it collect lost diaries from partygoers.
Ah, sorry about that. You might as well close that nuisance of a collapsible. Don't leave just yet, for I can provide you with some… interesting stories.
I just thought of something that would intrigue you! It's a story of a very unique boy, just like you.
This boy was a survivor! Indeed he was. Whether it was his skills or his luck, it was always on his side. Well… that's until he entered my level.
Here, I'll even read out his story for you…
Don't:
- Give it a reason to stalk you. Keep possession of lost diaries only when absolutely necessary.
- Try to follow it. Following The Mail Carrier has left many wanderers astray.
- Read