Although your employee's privacy is important, the Interception Act does allow you to intercept your employee's communications.
BUT only under these four conditions.
You may read the contents of your employee's email under these four conditions:
Just bear in mind that it's unclear what the Interception Act means by the phrase 'in the course of your company's business'.
If this includes private emails sent during business hours, then this may give you the right to read them. But if it only means you can look at emails sent for business reasons then this isn't a licence to read private emails, even if they are sent during business hours, warns the Labour Law for Managers Loose Leaf Service.
So, until the courts provide clarity on this issue, you need to tread extremely carefully in this area.