Sorry to repeat Question I forgot to inclued a bit.
In the Organisation I work for we occasionally send out bulk mailings to members of the public or other companies. A guy in our dispatch office always opens one of the bulk mailing letters to see what it is - even if it is addressed to an individual, can this be done or am I right in thinking once the envelope is sealed the contents are private and for the addressee only? The guy seems to think it's his right to know what it is as he and the other guys have to process the mailing. Must add he's opening it just to be nosy, when he could easily ask the people sending the mailing what it is without having to open any letters.
If the company you work for are not alerted he could add to the postings or worse and bring the company down. You should inform someone to put a security camera up.