The Return to Sender mission in Control AWE is a fun trip down memory lane for anyone who remembers chain letters. While real-life ‘spooky’ chain letters don’t come true, Control’s weird world means that protagonist Jesse Faden can’t take any risks over not sending the one she finds.
To begin this side quest, you have to head to the Shifted Offices area of the Investigations Sector. You progress through this area as you play, so once you find the Control Point in this region, look for a set of mail delivery tubes nearby. The chain letter is on the table in front of it. However, if you missed this on your initial playthrough, you can fast travel to this Control Point to grab it.
Once the letter is in your possession, you have to copy it three times and distribute it around the Investigations Sector. To photocopy the letter, fast travel to the Operations Center. Take out any Hiss enemies you encounter, and then head to the back area of the ground floor. This is the part of the room opposite the giant map of the USA.
There is a printer on this back wall. Interact with it three times to produce three copies of the letter. From here, you need to fast travel to three sectors — the Utility Corridor, the Abandoned Offices, and the Observation Deck — to post the copies of the letter.
Fast travel to each one, and use the mail delivery tubes to send them off. Any tube system will do, so don’t worry about picking an incorrect one. Once that is complete, fast travel back to the Shifted Offices to locate the source of the chain letter. Interact with the Altered Item in a newly discovered room nearby to complete the mission.