Why do I have 8.3 GB mail on my hard drive even when using gmail?
This is a feature of the default set up of Mail.app on OS X. It is storing all your messages for "offline viewing" you can turn this off.
Go to Mail > Preferences click on Accounts
Click on your Gmail account on the left
Then click on the Advanced tab.
Under "Keep copies of messages for offline viewing" set that drop-down to "Don't keep copies of any messages" '
Also make sure that you gmail e-mail account is setup as IMAP and not POP3 you can see the type under the "Account Information " tab.
Why, because Mail.app keeps a local copy of your mail (in case you are offline, and to avoid downloading 8.3 Gigs of mail every time you use Mail.app). The reasonable way to go about the issue is to
- sort your mail and remove stuff you neither need/want anymore, then
- Stop using Mail.app and use GMail online if having local copies of your mail bothers you
- you could disable your GMail account, delete all your mail, then you can create a second GMail account, forward there ONLY the emails you'd like to have on your laptop and set up this 'private important account' in Mail.app for local offline access.
The fact that your mail is in the cloud means that it is on your laptop -- GMail would not go to Apple Cloud by itself.
You can configure the way Mail.app handles local copies in the definition of the mail account:
