Embedding QR Codes into Event Confirmation Email Messages
The messages system is built to deliver the emails, QR and barcodes in the most reliable way to attendees. Some email clients/programs block images to be loaded and block external urls to load images. Blocking images and external urls can result in the barcode/qr code not loading.
Event Smart Ticket Notice confirmation emails require attendees to click a link to get their ticket(s), but it is more reliable than delivering their barcode in the email.
However, you can use the Google Charts API service to build the qr code into their email. Adding html code like this into the confirmation email would embed their QR code into any confirmation email.
<img src=http://chart.apis.google.com/chart?cht=qr&chs=200x200&chl=[REGISTRATION_CODE]&chld=H%7C0 alt="QR Code" />
In addition, you could also let them click the link to get their email in another browser if the code got blocked by their email program from loading the image and the external link. That way they could get the ticket still.