QUOTE(rcrd2111 @ Aug 7 2007, 10:07 AM)

Thanks Andrew... I've sent to three addresses, Yahoo, Plusnet and ntlworld. None has arrived and I've tried sending several test emails over the last seven hours, including recently.
But you don't say you've actually tried to troubleshoot anything. The most basic thing to try, send an e-mail to one of those 'failure' points, but include a CC: to a place that 'works' .... That gives you a clue as to whether things are working at all, plus it gives you header data to work with when talking to the folks that run the 'failure' servers ... date/time-stamps, message-ID, etc.