Can you help me repair my email settings?

I've been using my desktop and laptop to send and receive email just fine until the last day or two, and now it doesn't work. I don't know why this should be.
The desktop is running XP with Outlook. I'm connected via a router to Sky Broadband (who's email is handled by google i understand). I can receive email fine, but sending has suddenly stopped working. I generally use accounts other than the one provided by Sky, and up until now I've just been forwarding it via the sky server.
POP3 mail server address - [****.org.uk]
SMTP address smtp.sky.com
Outgoing server requires authentication (use same settings as incoming)
Ports 110 and 25
Also, similar problems with the laptop, except that's running vista. The error log says something about 'server rejected the login', and 'must start TLS'. I've tried changing the outgoing server port to 587 with SSL, but it doesn't seem to help.
Any ideas? ta

I can't solve your problem but I had the same problem with outlook so I stopped using it and have recomended others wit this problem to do the same.
If it's any consolation, you are not alone with this issue.

My SMTP Server {SMTP.sky.com} suddenly stopped working also, I now use Yahoo.