You may have to save e-mail to be in compliance with the law, and you will definitely want to save e-mail for business and HR reasons. Still, only 48% of U.S. companies have any kind of formal e-mail archiving system in place, according to the Radicati Group.

For many businesses, storing e-mail just means letting old messages sit on the mail server, printing out important correspondence and filing hard copies, or making backup tapes of e-mail servers and hard drives every month or so. None of those approaches really cuts it. For one thing, letting e-mails pile up on a server is a great way to slow down a system's performance.

For another, if you ever need to find any of those old e-mails--if you get sued or a regulator wants a look at your records or if you want to fire an employee for sending pornographic e-mails--you'll need some organized indexing system to help you find them. This means not only storing business correspondence, but also establishing a means of searching e-mails and attachments. "The cost of electronic discovery these days is often more than going to trial," says Ian Ballon, a trial lawyer specializing in intellectual property and Internet law with the Manatt Phelps law firm in San Francisco.

To manage the constantly growing volume of e-mail that needs to be saved, more businesses are turning to archiving companies (five big ones: KVS/Veritas, iLumin, Iron Mountain, Zantaz, and AXS-One). These companies offer hosted (they save your data off-site) or in-house (they set you up with the hardware and software) solutions. A key element necessary for either is a dynamic search engine, which allows users to find the proverbial needle in the haystack. Waterford Technologies and Smarsh Financial Technologies gear their products for small to midsize businesses.