Full mailbox
People trying to send me email keep getting 'mailbox full' message - when it isn't! What can I do about this?
MacBook, macOS 10.14
Question marked as
That's a message from the server, not from Mail and has nothing to do with the storage available on your Mac.
Log into your email provider's web portal and see how much you have stored on the server.
You may also be able to see the storage quotas by ctrl-clicking on the Inbox of an account and choose "Get Account Info."