I certainly do not wish to upset any letterboxers and totally respect their hobby as I hope they respect ours. In fact many participate in both hobbies and I agree with the “live and let live” sentiment.
I have never advocated that anybody should remove a genuine letterbox from the moor but I do maintain that the very obvious rubbish boxes, often ice-cream cartons and saturated, should be removed as they are litter. Surely it is up to all of us to look after the moor we love and to remove litter whenever we see it.
As for reporting these boxes to the DNPA, that is not sensible. They point out on their web site that they are not responsible for litter removal, but do so unofficially. They clearly have no resources for this aspect of maintaing the moor and it is up to all those who love the moor to clear litter when they see it.
I will be interested in seeing other replies to this topic and will be very happy to amend or delete that note on my cache if that is the general consensus.