No you don't. Not anymore. With cloud-based services becoming more and more mainstream, and what with up to 20Mb broadband you really don't need an inhouse server for your small business. Let's look at a few quick reasons why:

1) Zero advantage to having an inhouse Exchange Server
In fact I'd go as far as to say you're at a disadvtange if you have an in-house Exchange server. In-house servers are more expensive to buy and maintain than hosted services, they aren't any faster and you still have to back the whole thing up (add extra expense, tape drives etc. here). Online services such as Exchange Online or Google Apps will give you what you want: Your email with a backup in place. Online services come pre-packed with redundancy and offsite backup so why spend thousands more to have a box in your office? It just doesn't make economic or logical sense anymore.

2) An expensive File Server
Many of my clients have Small Business Server installed in their offices and other than running Exchange it's acting as a glorified file server. Rather than spend thousands on hardware and software for your Small Business Server, rather install a Network Attached Storage Drive (NAS). This is just a fancy word for an external hard drive. Most of the decent ones on the market these days come in at well under £1000, and have file/folder security and remote access built in as standard.

3) Throw your tapes away
A large percentage of backup tapes will fail to read when you actually need them. This is due to the fact that most people don't regularly replace their tapes (as recommended by the manufacturers). This means no matter how diligent you may be in taking your beloved data offsite, you may as well throw the tape in the bin if it won't read! More money to be saved here by replacing your expensive tape drive and tapes with online backup. I use Mozy which costs just 50p/Gb - you can't go wrong with that!

So before you start spending thousands on getting your own in-house kit to host everything, speak to me and I'll explain why if you're a small business, you simply don't need to do this anymore.