McAfee is to acquire email and security vendor MX Logic in a bid to improve its security as a service offering.

Dave DeWalt, president and CEO of McAfee, said the deal would bring McAfee "world-class e-mail and web defence, including archiving and business continuity services, extending our proven expertise in providing cloud-based services to our customers."

By coincidence, McAfee and MX Logic both published periodic threat reports this week each detailing how spam has hit all-time highs.

The acquisition, worth about $140 million in cash is McAfee's third this year. In May, McAfee bought Solidcore Systems for its whitelisting technology and in February it bought Endeavor Security, a privately-held maker of IPS/IDS technology.