The sound comes from Postal, the controversial shooter series by Running With Scissors that began in 1997, where the Postal Dude is the unhinged protagonist voiced in later entries by Rick Hunter. Short voice clips from the games circulated on soundboards and in video edits because the lines are brief, recognizable, and delivered without emotion. This yes survived as a reaction staple in gaming communities, shared for ironic agreement rather than for any specific story moment, and remains popular alongside other game voice memes.
About this sound
Postal Dude saying yes from the Postal game series, a short affirmative voice line used for reactions, edits and meme replies in gaming videos and streams.
The Postal Dude delivers a flat, deadpan yes in less than a second, with no excitement or hesitation behind it. The delivery is dry and slightly sarcastic, which makes the simple agreement feel funnier than a normal yes. It works because the contrast between the mundane word and the character's notorious personality creates instant comic timing. Viewers recognize it as a blunt confirmation, often used when a plan is obviously bad or a question deserves the least enthusiastic approval possible, and the brevity lets editors drop it cleanly into any pause.