On: Cyberattacks in 12 Nations Said to Use Leaked N.S.A. Hacking Tool

[cortesoft]

That will protect you from data loss, but not data theft.

[corford → cortesoft]

Data theft is a separate issue. Whether your using gmail, your own mail server or an account with your ISP; if you're machine is compromised all bets are off (including all your other files, not just email). At least with a backup you wont lose your data as a result of the theft.