Email On Both the Desktop and the Laptop?

RapterOfParadox asks: "I recently purchased a new laptop and have everything configured except for my e-mail. I've always liked having a single location where I know my e-mail is safe, secure and gets backed up automatically. If I've needed access to new messages then I use webmail, since I close down the email client when I leave the house. I'm currently using Outlook XP for my desktop and was thinking about using the same for my laptop. My only issue is that I'm a little weary about using only my laptop for storing e-mail, since it's a lot more likely to fail. I've been thinking about just synchronizing my Outlook data directories at login, or even using IMAP. Has anyone seen/bought/built an e-mail client that will allow me to have my main e-mail client on my desktop and then update my laptop e-mail client when ever I'm in range, or through a personal IMAP Server?"