I've installed Intrepid Ibex (Ubuntu) and I've configured Thunderbird correctly (as far as I can see) with the following:-

full email address for usernames in pop and smtp, port 995 for pop and 587 for smtp, ssl for pop and tls for smtp although I've tried them all variations.

Mail downloads but when I try to send anything I get the sending message bar which just sits there looking like it's sending but doing nothing until it times out.

All the settings are correct according to the advice on the web.

The thing is, Evolution does the same thing!

Please help.

Check your gmail and firewall settings.
Do you need authentication for smtp?

Solved it, odd this but if I use Gmail for smtp it works! So I'm using Googlemail for pop and Gmail for smtp. I was under the impression that as I'm in England that I should use Googlemail so I never thought to try Gmail.