THe mailbox system is pretty archaic

[Akimori]

The game suffers from what I call "menu hell" pretty badly. A lot of very slow systems that require a bit too much fiddling to use comfortably, and way too many submenus. The worst, regarding the mailbox at least, is when you try to retrieve something a half second before you're supposed to so you have to wait an extra full second to do so. Then you can't delete the letter from the inbox anyway, so you have to switch tabs and do it there. Just ugh.

edit: too friendly with the comma key

Or when you want to retrieve something from a letter and you get the occasional "mail processing error", and you have to go to another letter, then back to that letter to actually retrieve them