they must see a lot of letters in a day and can no doubt work out the content. so they could easily tell if you have a reminder to set up a direct debit for your TV Licence, for example
Probably not. My postman isn’t even attentive enough to pick up on it when mail with my name on has the neighbour’s address on it, etc, so I doubt he’s bothered about what’s inside the envelope.
The postman at my parents old house managed it. I reckon it should sink in fairly quickly when your dealing with the same names and addresses on a daily basis.
The current one is a right miserable twat anyway. Always has earphones in and avoids eye-contact if your in the street at the same time as him.