I have long had an additional paid-for email account from .Mac, which provides webspace, homepage design etc etc for Mac users. At first I didn't particularly use the email addy that came with it but as ntl's service has gone to hell in a handcart I found myself using it more and more and eventually I bought an additional addy for my missus (only an extra £7 per year).
We have diverted our ntl accounts to our mac.com mailboxes, and I haven't had any problems since. TBH, I don't even notice when ntlworld is 'experiencing problems' with email any more; my email client is set never to automatically check @ntlworld.com automatically so error messages are a thing of the past...