ONE OF OUR CLIENT MAIL WAS RETURN WITH DECEASED ON THE ENVELOPE?
That means Dead or are you still confused?
That would tend to imply that person is no longer living. What's your question?
So what's your question? The PO says your client is deceased, so you take them off your mailing list!
There is a 50% chance that the person is dead. If it is a bill, though, you will want to check the obituaries to see if the person is really dead. I worked for a collection agency a while back and people would try to 'prove' they were dead to get out of their bills. AND..THE MOST COMMON RUSE WAS TO WRITE ON THE BILL THAT THE PERSON IS DECEASED AND MAIL IT BACK - RETURN TO SENDER. Then, of course we would have to call and pretend that we were a friend or relative or had a job offer...any thing to get that person on the phone. ...and of course...if we couldn't collect...the company would 'sell' the debt to another company that was not as scrupulous as ours.
If the mail was a bill, then you will probably have to file a claim with the deceased's estate. Or you can go to the funeral and harass the widow.
So, they are probably dead...
Means they died
If it was an ad, take them off the mailing list. If it was a bill, send out another addressed "To the estate of...(your client's name)" and get paid.