I sent a glassed, framed project to England from Missouri and it arrived just fine. Now, granted, it was wrapped in bubble wrap and also packed in a box with three Moshi pillows! But so far, with suitable packaging care, none of the "care" packages my English pal and I send back and forth have arrived damaged. Also, something I've been doing for the next framed project that needs to be mailed, is saving the packaging that comes with books from Amazon or Barnes & Noble. I think with the proper care, it will work just fine to lessen the worry of glass breaking.
Tegan