I've been aware that some of my emails haven't got through to people on
this list and, also, that I have not been getting every email from others.
Checking our mail server logs it would seem that any email from a sender
whose mail server uses DKIM is likely to be rejected by recipient
servers that check DKIM. This includes dev@NuttX emails because the
apache mail reflector (if that's the right terminology) causes the DKIM
signature to be corrupted.
Perhaps that's just the way it is - I'm not sure.
Since we have also had continual issues with our genuine work emails
being rejected by gmail (and only gmail) because of some DKIM issue I
just can't work out, I have disabled DKIM from incoming and outgoing
emails on our server as a temporary measure.
Hope this helps others who have not been getting dev@NuttX emails.