Morning Frank.
If NTL are messing around with their POP servers then you won't be able to access it. You could try pinging the POP server when you can't get mail to see if it's even available. You may still be able to send mail because most ISP's host the SMTP service on another box.
As long as you have web access you should still be able to get at your hotmail, whether you access it via outlook or a browser.
I don't use NTL (I'm Telewest at home, about to be upgraded to 1MB for free

) so I can't say whether they have been having outages but I would assume they would have a website listing their current outages - I know Telewest do and aren't they really the same animal?