Because of the sheer quantity of spam that corporate users receive--in 2005, 45% of their daily average of 132 messages, according to the Palo Alto, CA-based Radicati Group--spam can dramatically swell the size of an e-mail archive and slow down indexing, search and retrieval.

Yet in the absence of clear directives from regulatory bodies such as the Securities and Exchange Commission (SEC), some firms are opting to archive all incoming e-mail--diet pill promotions and all. Rather than try and second-guess the regulators, some firms have decided it's less risky to archive everything, says Mary Kay Roberto, senior VP and general manager for Veritas Enterprise Vault.

But archiving spam is probably overkill given the prevalence of anti-spam technology, says Pete Gerr, senior analyst at Milford, MA-based Enterprise Strategy Group. "What the SEC is most concerned with is the consistency of your policy," he says. For example, do ...

"The SEC is practical," says Kon Leong, president, CEO and co-founder of Santa Clara, CA-based ZipLip, which makes the Unified Email Archival Suite. They understand archiving spam is silly, but they don't want its deletion to be used as "a way to worm out of compliance," he says.

As a practical consideration, it's probably best to avoid filtering out spam at the point of archival, where "it's much harder to do," and after it's been delivered to the user, says Gerr.

A better way to rid yourself of unwanted e-mail may be to subscribe to a third-party spam-deletion service, suggests Dan Nadir, VP of product management at FrontBridge Technologies, which provides e-mail archive, continuity and security services, including spam filtering.

"The consensus is that, regardless of whether an individual message is spam, if it was never delivered to you, you don't have to archive it," Nadir says.