A third of office workers have been sent sexually explicit or racist material by colleagues, while 7% say they have e-mailed company-confidential information outside their organisation, according to a new survey.

The poll of more than 2,000 UK employees, commissioned by security specialist Clearswift, suggests that even though most employees are generally aware that sending inappropriate e-mails could be dangerous to their company, abuse of e-mail systems continues regardless.

"The amount of inappropriate content making its way round UK businesses' e-mail systems is astounding," said Jon Lee, chief executive of Clearswift. "Employees need to stop and think about the trouble they could get in if these e-mails got into the wrong hands."

According to the survey, only 10% of respondents said their organisation had sacked an employee for sending inappropriate e-mails.

Many companies do have an e-mail policy, but the survey found that just half of respondents fully understood their employer's guidelines. One in ten did not understand their company's policy, 24% said that their companies did not have a policy, and 15% of respondents did not know either way.

Emma Grossmith, an employment law specialist with Pinsent Masons, said employers cannot afford to ignore e-mail and computer misuse. "Apart from the potential disaster of confidential information being leaked, employers run a real risk of being sued if e-mails sent to or from their employees are discriminatory or defamatory."