Before you print
How big should it be?
Rule of thumb: printed width ≥ scanning distance ÷ 10. Pick the surface above and the studio sizes the code for you, then checks the printed module size against what a press can actually hold.
Questions people actually ask
Their phone opens its mail app with the address, subject, and message already filled in. Nothing is sent automatically — the scanner reviews it and taps send themselves.
Yes, both are optional fields. Prefilling them is great for feedback requests or support tickets — the scanner just adds their details and sends. You can also CC a second address.
Yes — separate several addresses with commas in the To field, and the same in CC. All of them appear in the scanner's mail app.
Not by us. The code is generated in your browser, free with no signup. The address is encoded in the QR squares themselves, so anyone who scans it can read it — only use addresses you are happy to share.
Want the detail? How email QR codes work — the payload format, what scanners do with it, and where it breaks.