Computers have been known to crash, so it's a good idea to save e-mails to an external hard drive. If you use an e-mail program like Outlook or Outlook Express, you can use the export wizard to create periodic e-mail backup files that can be saved to an external hard drive. For any e-mail client, you'll need to locate your e-mail data files and copy them to an external drive for safe keeping.
Plug in your external hard drive and connect it to your computer.
Locate your e-mail data files. Some programs store data in the application folder. Check your program's "Help" file if you can't find your e-mail data. If you're using Outlook or a program with an export function, skip this step.
Make a file on the desktop to temporarily store your e-mail files.
Open your e-mail program and go to "File." Look for an "Export" option. If you see one, click to begin the automated export wizard.
Choose the files you want to back up. In Outlook you'll want to back up the ".pst" files. You can select all the email folders or just certain ones.
Export the email files to the backup folder you made on the desktop. If you're manually copying the files from the application folder, make a copy by right-clicking files and selecting "make copy" then drop them into the folder.
Take the backup folder you just filled with e-mail data and drag it to your external hard drive. Open the folder to make sure all the files transferred.
Delete or move the temporary copy you created on your desktop.