if the message never achieved a physical form such as printing, does the message exist?
if the message stopped existing, but nobody was there, did it make the trash-can sound?
if the message stopped existing, but nobody was there, did it make the trash-can sound?
The physical bits do exist, though, on the storage medium. Now, of course this does not match our usual image of existing, since the bytes were technically always there, but it still exists in the physical world.
You can actually make the same argument with a letter: The paper and ink were there before, the pattern ist what brought it to existence.
I know the answer for the case where this question refers to something on my pc. I have disabled audio warnings, alerts, etc so if the message stopped existing and I wasn't around to notice then it clearly does not make a trash-can sound.
Is the goal to have it be readable to the naked, nominally working human eye? If so then I’d wager you could use magnetic paper as storage if you were a particularly persistent driver developer.