After a certain inbox capacity, MIT inboxes receive an e-mail warning that the inbox is quite full and should be cleared more. It turns out one can still use one’s e-mail functionally even after one’s inbox reaches capacity (but others might get annoyed at you because of the bounceback e-mails they receive about your inbox capacity). Here’s a chart of how full (in %) my inbox was over the past year, according to the inbox capacity e-mail I got on that day.
There are a few gaps in this graph which probably represent times when I deleted the warning e-mail, possibly even for little bits of space. The one big gap in the middle, however, might actually be a segment of time when my inbox was legitimately filled to less than the warning capacity.