Criminal diversion of letters from addressee

Every person who, not being an officer of the Post Office, wilfully and maliciously, with intent to injure any other person, opens or causes to be opened any postal packet which ought to have been delivered to that other person, or does any act or thing whereby the due delivery of the letter to that other person is prevented or impeded, commits an offence and shall be liable on conviction to a term of imprisonment not exceeding five years.