Sorry you're having the same problem. I have recently tried sending test e-mails from my Wanadoo.fr address to ten friends with ntlworld.com addresses. Results: Not a single one got through. My 18th & 19th messages to
service.client@wanadoo.fr remain unanswered, as do the previous 17. Somebody, somehow, has got to kick these lazy so & so's into action, but I don't know how. Ntlworld seem equally uninterested (they have not replied to any of 19 messages about this).
So I suggest to your correspondents that they change ISP. If enough people leave Wanadoo.fr, saying why they are doing so, perhaps they might wake up.
Or could we get one of the national Newspapers to run a story on this?
Bon Courage
Don