A high court judge has ruled that companies do not have a general claim of ownership of the content contained in staff emails.
The decision creates a potential legal minefield for the terms of staff contracts and an administrative nightmare for IT teams running email servers, back up and storage.
The judge ruled businesses do not have an "enforceable proprietary claim" to staff email content unless that content can be considered to be confidential information belonging to a business, unless business copyright applies to the content, or unless the business has a contractual right of ownership over the content.
The ruling was in relation to a case involving shipping company Fairstar Heavy Transport and its former chief executive Philip Adkins.
Fairstar had already won a court order preventing Adkins from deleting certain emails that had been forwarded to him from the company's servers.
Although Adkins had been working for Fairstar he was actually under contract to do so by a separate company called Cadenza Management. Adkins lost his job as chief executive when Fairstar was bought by a rival company.
Whilst employed by Fairstar Adkins had agreed a shipbuilding contract with a Chinese shipyard. A dispute had arisen about the potential cost liabilities Fairstar faced under the contract terms.
Fairstar claimed that it in order to address the issue, and also to respond to an investigation into alleged accounting irregularities being undertaken by the Oslo stock exchange, it needed to have access to the contents of Adkins' emails.
Fairstar claimed that it automatically deleted the emails that it forwarded through its servers to Adkins' Cadenza account when he worked as chief executive.
But Justice Edwards-Stuart ruled that the company had no right over the ownership of the email content and therefore rejected Fairstar's request for an independent inspection of Adkins' emails to take place.
The judge said that there was nothing set out in case law in England and Wales that provides that there is a general proprietary right in the content of information.
He said: "I can find no practical basis for holding that there should be property in the content of an email, even if I thought that it was otherwise open to me to do so.
"To the extent that people require protection against the misuse of information contained in emails, in my judgment satisfactory protection is provided under English law either by the equitable jurisdiction to which I have referred in relation to confidential information (or by contract, where there is one) or, where applicable, the law of copyright.
"There are no compelling practical reasons that support the existence of a proprietary right - indeed, practical considerations militate against it."
Justice Edwards-Stuart added it was "quite impractical and unrealistic" to determine that ownership of the content of emails either belongs exclusively to the creator or the recipient of an email.