Proofpoint has acquired Fortiva, a seller of email archiving services designed to speed up the process of responding to legal discovery requests.

The acquisition will beef up the company's Proofpoint on Demand software-as-a-service (SaaS) product line. Proofpoint completed the acquisition over the past few days, a spokeswoman said via email. Terms of the deal were not disclosed.

Fortiva's Archiving Suite works with Microsoft Exchange servers and has been sold through Microsoft Online Services and MessageLabs. The service will be renamed Proofpoint Email Archiving over the next few weeks, the spokeswoman said.

With offices in Stamford, Connecticut, and Toronto, Fortiva has a staff of 40. Key management and technical employees will form an email archiving business unit within Proofpoint.

Proofpoint was founded in 2002 by Eric Hahn, formerly chief technology officer of Netscape.