How can I delete all cached/offline email from the Mac OS 'Mail' program on my SSD in Mac OS El Capitan? I have 2 Gmail accounts and an Exchange account for work. I'm running out of room on my 256GB SSD, so I need to clear out any/all data that I can.
I also want to ensure no new mail get stored locally. Basically, I just want the mail accounts to sync to the IMAP/Exchange email servers via the internet and never rely on any local storage. This is a hardwired Mac Mini, so it's never offline. Thanks.