Windows/Mac/Linux: Gmail Backup saves and restores complete archives of your Gmail email account using Gmail's built-in IMAP capability. The Windows version comes with a simple graphical interface — just enter in your email address and password, select a backup folder, and click the Backup button. It will save your messages in Microsoft's EML format complete with attachments. The Linux version (which also works with Mac OS X) is command-line only. Besides enabling offline access to your archives, you can use the restore feature to upload messages to another account, making it easy to transfer old messages to a new account. I supports regular Gmail accounts as well as Google Mail in Germany and Apps For Your Domain email accounts, as long as POP/IMAP access is enabled under Settings. Don't want to risk using a backup tool that's still in development? Try our guides to backing up your mail accounts to your computer with Thunderbird, Fetchmail or Getmail. Gmail Backup is a free download for Windows, Mac and Linux. Thanks, jonny6pak!