Waitrose they do an 0845 &/or 0844 number and you can pay by the minute or 15GBP per month. Webmail is functional and easy.

I pay by the minute, and even running websites I average about 8GBP per month. You have to use at least once per 30 days this way.
their anti-virus e-mail detection is first class and the telephone hotline is an 0800 number and they seem to know the answers to my questions and I only ring when I am really stumped.

I also use UK2.net because my domain name and primary e-mail is hosted by them. The actual dial-up is dis-owned by UK2 and they refer you to Tiscali who cannot answer questions that don't include Braodband, they end-up sending blank e-mails which is netspeak for "end of subject". Pay them by the minute and I don't pay much to them I can tell you.