The form mail notifications have not been working for the last day or so. I'm not sure what caused the problem, but I think I have solved it by reconfiguring the postfix mail sender on this system, so hopefully it is back working again now.
It turns out that a spam filter on one of the mail relay computers was eating the mails because the IP address wasn't being resolved properly. This may also explain why some people seem to have had problems in the past with email notifications from this form. With any luck, this system will now be more reliable.
- Phil