Symantec Enterprise Vault is "kind of the product to beat" in terms of market share and functionality, said Goodall. But a lot of document management and storage vendors will have solutions, he said.

Nearly every integrated vendor like HP and IBM has its own solution for Microsoft Exchange or Lotus Notes, said Pearson. But there are also smaller companies like Barracuda, which has an interesting hybrid solution for SMBs, he said.

If you are considering a cloud-based e-mail archiving solution, "the most important aspect and maybe the key differentiator between alternative solutions is in the service level agreements," said Paul Wood of .

The SaaS model works for any size organization, said Wood. "A lot of organizations now have reached that tipping point and looking at the same solutions that large Fortune 500-type companies will have ... but it will be available to them at a scalable cost using a SaaS model so they don't have to invest huge amounts in their infrastructure in order to provide that solution and that capability.