Can I send in blank cards or card stock? If so, is it 10 a month, like other places seem to be?
Also, can I use return address stickers? Mine get through at High Desert, but not Mule Creek, so I figured I best ask!

Can I send in blank cards or card stock? If so, is it 10 a month, like other places seem to be?
Also, can I use return address stickers?

You can send stamps, 10 a month rule applies; cardstock ok. The usual: no glitter, stickers. So, no return address stickers/labels. I have no idea about the blank card, I've never sent one. Hope this has helped!

Ally