Dear Brad,
Many thanks for taking the time to reply, very helpful.
The headers expose the sender address and domain (the message-ID does the
latter, of course), which makes the 'hide sender...' option a bit confusing.
I must have misunderstood the thinking behind the "Hide the sender of a
mess
I have tried searching the archives for this, but to no avail - my apologies
it this has been covered.
I have enabled the options to hide details of posters to my lists - however,
subscribers can view the email headers of messages from the lists and easily
see who has sent not only the original