I may mat mine - then again, I may not. That all depends on the image and what it looks like.
But one thing is certain: They will be unmounted. Not only because I don't have a mounting press (but my local framer has one, and does exellent work), but because my experience is that mounted prints have a significantly higher risk of being damaged in the mail. The mat is stiffer, but it will break instead of flexing. If the print is mounted, it will break with the mount. If it's only attached with hinge tape or photo corners it will be undamaged even if the mount is a total write-off!