Senders of emails are often unaware that the content of their messages is being monitored and recorded. Just as email originated in America and spread to Ireland, so too has the corporate practice of monitoring employees' email.
About 95 per cent of large corporations have an email monitoring policy, says Mr Paul McEwan, technology manager of Citibank Ireland, who confirmed that email was monitored there.
Ulster Bank and Arthur Andersen also confirmed they monitored their emails. An AIB spokesman said "our systems are well capable of monitoring the content of emails" but he would not comment on whether the bank does so.
Mr Robert Baker of Baker Consultants, an Irish computer consultancy, outlined the monitoring methods. "In the first instance, it can be monitored in the systems folder, which is roughly the equivalent of opening it in the sorting office. In the second instance, it could be read as it travels along the corporate network, which is the equivalent of it being read by the postman. In the third instance, it can be read in the recipient's mailbox, which is the equivalent of having it opened in your home.
"Users are not aware that their communications are being recorded and stored at night as part of the standard corporate back-up," he said.
Monitoring systems generally check for certain keywords. No distinction is made between incoming and outgoing email. In the case of Citibank these words are of a pornographic or racist nature or derogatory words regarding a colleague, client or competitor.
Mr Baker estimated that only 3040 per cent of email to and from corporations was of a business nature.
The legality of these monitoring systems depends on the terms of the employment contract. A right to privacy exists in the Constitution and the European Court of Human Rights. But this right exists only where a person has a reasonable expectation of privacy and can be waived in a contract.
Where a contract states that the employer's equipment can be used only for business purposes and that email will be monitored to ensure the employee stays within these terms, monitoring is legally permissible, according to Mr Eoin O'Dell, lecturer in law at TCD.
"These contracts are becoming increasingly common in Ireland as American corporations set up here, bringing with them American employment practices," he said. "Irish companies are now beginning to adopt the same conditions.
"If there is not a clause saying `either or both', it becomes more complicated; terms can be implied into a contract if it goes without saying that they should be there. A term that employers' equipment can be used only for business purposes might be considered such an example; but such a term might not allow for the employer to monitor his employees' email."
An employer could probably monitor a worker's email without express agreement if he had just cause to believe it was being used for non-business purposes, said Mr O'Dell.
The increase in computer monitoring was described as "an infringement of people's liberty and privacy" by Ms Siobhan Ni Chulachain , co-chairwoman of the Irish Council for Civil Liberties. "It is unacceptable where employees have not been told.