They’d be like “hey now, this didn’t cost you that.”
But would not that depend on how OP's time is valued in this case? OP could argue that their expertise costs $14000/hour ($70000 over 5 hours). I am sure that they would argue the hour cost, I have not clue how the IRS handles something like this.
There is not alternative that is selfhosted to my knowledge. There is PushBullet with a free tier that allows for sending files. You could also use Discord and send messages via their API, and I assume that Matrix has something similar (but I have not looked).
You could also upload them to something else (Paperless or some web/file server) and send a link in your notification. A link can be displayed as a button with actions tag.