According to DaisyDisk, I've got a 27GB folder at Library/Mail/V2 and then another 23GB folder at Library/Containers/com.apple.mail/Data/Library/Mail/V2. Are these duplicates? Any idea which one I should delete? Also, since my email is hosted via Gmail and is IMAP, shouldn't all of my email be stored on the server? Is this just a copy of all of my mail being stored on my computer so that I can access it quickly and without having to be connected to the Internet? That's fine with me as long as it's only 27GB or 23GB, but 50GB is too much space as my hard drive is only 128GB.