More than two thirds (69 percent) of office staff can not send or receive emails larger than 10MB in size, says Virgin Media Business.

Research by the UK business ISP also revealed 89 percent are unable to send or receive emails in excess of 15 MB. Furthermore, the average worker can only send emails of up to 12.5MB in size and has just 140MB of space in their mailbox.

Virgin Media Business said outdated limits on email size are making it difficult for workers to send large file attachments, such as PDFs or video files, and as a result staff are increasingly going to extreme measures to ensure that important messages are received.

For example, many office workers attempt to reduce the size of the files they want to send, while others create extra work for the IT department by calling on them for help.

However, the ISP said it was seeing a trend towards staff uploading files to file sharing sites or sending them via personal webmail accounts.

"Email is an integral part of their job, but it can also be a major source of frustration. Many workers regularly find that emails bounce back because the recipient's mailbox is full or an attachment exceeds email size limits," said Andrew McGrath, executive director, commercial, Virgin Media Business.

"Often staff will attempt to get around the problem by sending a file using a personal email account, file sharing website, or unsecured USB device. But despite having the best intentions, these solutions can create more problems than they solve by potentially putting confidential data at risk."

McGrath said many of the existing limitations were designed to conserve bandwidth, but advances in networking and communications technology mean that they are no longer necessary and could be hindering workers, whilst potentially making corporate data vulnerable.

"Sweeping these email restrictions away could free up time for IT staff to focus on driving real business change through innovative technology."

See also: 74% plug personal gadgets into company network