Bob; USPS is unable to determine anything about undeliverable mail that is not insured or does not have a receipt or confirmation number.

I think that the club membership officer, Ralph Myers, would be able to tell first of all; if the individual has renewed their dues; and secondly if the optional first class delivery has been paid for this current year.... or if there is a problem with the address on file. Anyone of these things would cause non-delivery of club mailings.