How to Backup & Restore Apple Mail
Apple Mail comes pre-installed on all Mac computers with the OS X operating system. If you are running Time Machine, you can use it to automatically backup your emails and account settings. However Time Machine uses extensive resources and many Mac users find it a complex program to operate. Backing up and restoring Mail by itself is relatively easy and takes only a few minutes if you know which files to copy and where to find them.
How to Backup Apple Mail
Quit Mail if the application is running.
Open the Finder and click your username under "Places" on the left of the Finder window. Open the "Library" folder. Then open the "Preferences" folder.
Locate the "com.apple.mail.plist" file. Click it once to highlight it. Then press "command" and "C" on your keyboard to make a copy of it.
"Desktop" under "Places" on the left of the window. Click the "File" menu and select "New folder." Name the folder so you can later identify it as your Mail backup folder.
Place your cursor on an empty place on the desktop. Click the desktop with your mouse while holding down the "control" key. Select "New folder." Name the folder so you can later identify it as your Mail backup folder.
Double click the new folder to open it. Press "command" and "V" on your keyboard to paste a copy of the file in the folder.
Copy the "Mail" folder located in the "Library" folder. Paste it into your new backup folder.
Copy your backup folder to an external hard drive, USB flash drive, or burn it to a CD, if you want to protect the files from hard drive failures.
How to Restore Apple Mail
Quit Mail if it is running.
Open your Mail backup folder.
Drag the "com.apple.mail.plist" file and the "Mail" folder into the "Library" folder under your username. A pop-up window will warn you that these files already exist in the folder. Click "Replace."
Open Mail. Your Mail accounts, rules, signatures, and email messages will be restored.