If you have a maximum size for mail accounts, the storage size should be prominently displayed on the main page. I got warnings about my mailbox size and am working on reducing my emails. However, when I try to find how much space I'm using (on my laptop view of my yahoo mail account) it is not readily apparent. You shouldn't threaten me about my account's size and then not let me easily see what it is as I'm trying to reduce it! Very frustrating!