The average UK worker spends 288 hours a year typing emails and sends more than 4,000 in the process, according to research.
A study into work productivity by O2 Business showed that more than a third of UK workers feel "overwhelmed" by the number of emails they have to deal with, with more than 10,000 emails entering and leaving their inboxes each year.
Some 59% of workers said they used email more than any other form of communication. This is despite the same research finding that more than half (56%) of workers believe phone calls are more effective ways of communicating.
Paul Lawton, from O2 Business, said: "Our research shows that there's often a reluctance amongst UK workers to pick up the phone even though it might be a better option."
O2's research also revealed the UK's biggest office pet peeves when it comes to communication; with unnecessary face-to-face meetings that could have been handled over the phone and the pressure to respond to emails straight way both featuring.
The difficulty of arranging meetings, and instant messaging systems designed to improve communication but becoming distracting also made the list.
The survey also showed that office workers in the South West receive the most emails each year; averaging 10,800 or 48 a day.
While those in the West Midlands had the quietest inboxes - receiving on average about 3,800 emails a year, or 17 a day.