Once you've imported your e-mail, you can easily search through it all, using sophisticated tools, such as searching by subject, message body, folder, attachments and so on. Searches are performed much more quickly than in your native e-mail client. And you can easily back up your e-mail as well, just by burning a backup CD of the archive.
Mostly, importing e-mail is as simple as pointing and clicking--although if you're going to import from your POP3 or IMAP account, you'll need to have your server location, and login information. MailStore Home says it will import and back up e-mail from numerous mainstream e-mail clients, including Microsoft Outlook, Thunderbird, directly from Microsoft Exchange, and Windows Live Mail. And it also says that it will import mail from POP3 and IMAP accounts, with limitations. For example, it can only directly import your inbox from POP3 accounts; to get more folder, you'll have to contact your mail provider.
MailStore Home is the free version of the software, and has some limitations, such as not being able to import Outlook .pst files--you'll have to import folders individually. Still, for anyone who wants simple e-mail backup and fast searching, MailStore Home is a keeper.