It's pretty much only allowed if there's an important reason for it. For example, to recover something invaluable (contract, code, report) that isn't available somewhere else and cannot be replaced. In that case that's also the only thing that them employer can look for. They can't open obviously unrelated e-mails. So before talking to legal, make sure you have a valid reason.
Not really, ECHR has already ruled on this.
It's pretty much only allowed if there's an important reason for it. For example, to recover something invaluable (contract, code, report) that isn't available somewhere else and cannot be replaced. In that case that's also the only thing that them employer can look for. They can't open obviously unrelated e-mails. So before talking to legal, make sure you have a valid reason.