Even after high-profile security breaches at Target Corp., Facebook Inc., and Google, a majority of board members are still using personal email accounts to share corporate information—and a third of them have misplaced a company-owned mobile device or computer in the past year.

All told, 56 percent of directors and 51 percent of C-suite executives are using personal email, rather than a corporate account, to send sensitive company information. That's one of the findings from a survey of 411 board members and governance officials from 11 countries conducted earlier this year by Forrester Consulting for Diligent Corp., which sells software for securing boardroom documents.

“Many board members are using what might have been their first email,” said Brian Stafford, CEO of Diligent. That includes services such as Prodigy, SBCGlobal, and even Yahoo, which has been hacked already, he said. Many of the older services lack newer security features.