SaaS plus e-mail archiving gets hotter and hotter.Today Proofpoint, the anti-spam and messaging security vendor, bought Fortiva. Fortiva provides an e-mail archiving service that combines an on-premises appliance with cloud-based storage and management. As you'd expect with an archiving service, it offers a host of e-discovery features, including search and litigation hold.

Proofpoint already offers its own SaaS solution for message security, called Proofpoint-on-Demand, which includes spam and malware filtering, encryption, and data leak prevention.

The e-mail archive will be offered as a separate service. Proofpoint says it has plans to integrate the two services, but declined to offer a timeline. The company also declined to discuss whether it has plans to offer a premises-based archiving product.

This has been a busy time for SaaS mail archives. Just last week saw the launch of a new service from Live Office. And in February, Dell purchased MessageOne, a SaaS provider of e-mail archiving, continuity, and compliance services, for $155 million.

E-mail archiving is a hot technology, primarily because of e-mail's central role in litigation. Companies that fail to produce mail (and other electronic information) relevant to a lawsuit can face fines and sanctions, and even risk losing the case.

Just ask Qualcomm, which got hit with an $8.5 million fine for withholding e-mail messages during the trial of its patent lawsuit against Broadcom.

An archive provides a central repository for e-mail. This repository can be indexed and searched, and IT can control retention/deletion policies. An archive also makes it easier to find and produce relevant messages.

The appeal of the SaaS approach is twofold. One is the low capital cost. Another is that provisioning storage becomes the provider's problem, not yours. When you combine the growing volume of mail with the need to properly store and manage it, a service merits a close look.

Proofpoint declined to say how much it paid for Fortiva.