Returning some items in mail after claiming others

I sent a few ability stones from one character to another once it hit the required item level. On the recipient I claimed the ability stones 1 by 1 because I knew I might not need them all if I manage to cut a good one. However now I have a good ability stone, I want to return the others to the sender however there is no option to do so? All I can do is pay pheons to claim them on the recipient or let them expire?