Yeah or have that folder synced to a PC running at home, and then have a service running on that machine that prints anything that shows up in that folder.
Create a white list, and if mail is coming from a white-listed mail then print the contents, otherwise discard the mail.
This is how my Deskjet 4515 is working besides GCP. It's a pretty neat solution. It even replies with a result e-mail. I hope that HP won't kill its services too. They've already killed the app side, but remote printing is still intact.
(I wish Linux had an equivalent to Folder Actions. They’re really nifty.)