If you do all your emailing via POP where your messages are stored locally only, one thing you might want to consider having is a backup email account. This way in the event something goes wrong or you accidentally delete an important message, you can have access to your messages.

Of course you will first need to have another email account. I would recommend Gmail, but any account will do. Then you just need to have a copy of your messages redirected to the other account. Note that redirecting is different than forwarding because it preserves the full email header (subject, date, time, etc.).

You can set up a rule to automatically do this in Outlook (look in the section titled “Automatically redirect incoming messages to another e-mail account”) or if you use Thunderbird you can use the mailredirect plugin. Unfortunately, the Thunderbird plugin does not automatically apply to incoming messages, it must be done manually. For other email clients, Google is your friend so a quick search should get you what you need.

Another benefit to doing this is if you use a web mail account, you can login from anywhere and view all your messages.