Research conducted by MORI shows that 55% of directors receive more than 20 emails a day.
Managers send more emails than directors but receive fewer, the research shows.
A quarter of the managers and directors interviewed send more than 30 emails a day and a further 40% send between 11- 30.
A quarter of those questioned said they weren't sure that email was confidential. Worryingly, perhaps, the most suspicious group was IT and telecoms executives, a third of whom thought email was insecure.
Despite security worries many companies, especially larger ones with international offices, use email to distribute business and decision-making information.
The research focussed on executives in financial services, marketing and law firms.