UK ISPs to collect information on every e-mail

According to the BBC:

From March all Internet Service Providers (ISPs) will by law have to keep information about every e-mail sent or received in the UK for a year

Whilst I have yet to see the annoying cry of "Nineteen-eighty-four" appear all over the blogosphere, I'm sure it will by the end of the day. What intrigues me is how it will work, especially regarding web-mail accounts. Surely if I use a web-based email account somewhere outside the UK (or most probably the EU), and emailed people whose accounts are also outside the UK, then no ISP would be under any obligation to store the data.

Email is increasingly being replaced by other forms of communication, so if you really wanted to contact certain well-known unsavoury characters without the government finding out just instant message them.