Nearly two thirds of employees would be worried about their colleagues’ abuse of company e-mail systems if they were the boss and 7 per cent admitted to having forwarded confidential company information to people outside the organisation, according to research published today.

The poll, commissioned by the internet security specialist Clearswift and conducted by the polling organisation YouGov, also found that 34 per cent of employees have received sexually explicit or racist messages from colleagues. This follows the sacking this week of four police officers who admitted sending racist text messages to colleagues.

Most attention devoted to e-mail security has focused on countering external threats from viruses or programs called Trojans, which can scan computer hard disks for sensitive information to send to a hacker. This research suggests that companies also need to be aware of the risks posed by outbound e-mail sent by employees.

"It could be someone sending out to an outside source for inappropriate use," said Jonathan Tait, Clearswift’s product marketing director. "They could be sending information out to a friend or competitor maliciously, or it could be accidental. People rush through sending e-mails and might put in the wrong e-mail address.

"The e-mail in most people’s eyes is seen as pretty informal, and people forget that when you’re sending it outside the organisation it’s not informal. It has the organisation’s domain name on it and the company is held responsible for that."

This has led to growing concern within organisations, according to Stuart Okin, a technology specialist from the consultants Accenture. "People want to be able to control their e-mail and improve security," he told Times Online earlier this year.

Mr Okin said that software developers are building systems that would limit selected messages to internal e-mail addresses or to a list of approved users. "If people do try to spread a protected document beyond its specified perimeters, then it will break down into a pile of meaningless electronic goo," he said. "That means that only a specified number of people will be able to see a document and that, say, they won’t be able to cut and paste its contents."

An alternative approach is to scan all sent mail automatically and look for signs of suspicious messages. Mr Tait said that software can look for keywords or file types associated with inappropriate or confidential information. For example, it may block messages containing obscene language and limit messages with spreadsheets, which may contain sensitive information, to internal addresses. The program can also quarantine suspect messages and allow them to leave the system only if they are deemed legitimate.

Mr Tait acknowledged that the software may not be able to detect all cases of abuse, especially if the sender is deliberately trying to evade detection, but he said that since individual users would not know the precise list of keywords that were flagged as suspect they could not be sure they wouldn’t be caught. That would provide a deterrent, he suggested.

The survey found that employees were divided about whether companies have the right to read the messages they send. A quarter were happy for work-related messages to be read but not personal mail, while 29 per cent said that companies should not monitor e-mail at all and 39 per cent thought all e-mail monitoring reasonable.

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