Thanks for that. Checking your homepage now.
Signed up three accounts to three different ntl email addresses,
signed up two to other addresses in succession. Nothing in the ntl, both of the non-ntl accounts got it instantly. Sent email from various accounts to ntl, arrived instantly. I think we know how we can conclude
(edit) Just checked SORBS database from where the received messages originated, 72.21.38.146 - not in the SORBS db.