I use http://www.virtualnames.co.uk for both private and business, and they have been superb for a few years now.
They do email redirection, with optional spam filtering, domain sales and hosting, and if you run your own www/email server they also offer a DNS-only service (which is great).
A few tips if I may:
Spam filtering does not work! I can write you an email which your spam filter will dump, on word analysis alone. It won't contain any filth, but it will fall foul of some word frequency analyser. I have totally abandoned spam filtering because I cannot afford to lose a single business email.
For extreme cases of spam, like me getting 1000+/day at work, there are more intelligent solutions, like a challenge-based whitelist system (which some outfits also provide, or you can implement the open source TMDA one which I use).
Step 1: Register a domain name. Say your name is Ronald Reagan. Register reagan.co.uk. It's dirt cheap. Or reagan2006.co.uk if the former is taken, etc etc.
Step 2: Get somebody like Virtualnames to host it, and redirect any emails sent to it to your real ISP's mailbox (nobody needs to know what that is and you can change it anytime; all you have to do is update the redirection at VN).
You now have unlimited email addresses of the form
[email protected]
[email protected]
[email protected]
[email protected]
etc
So, when you go to some new website which asks for an email address, make one up on the spot
[email protected]
Then if they sell it to a spammer, you can set up a spam filter on it.
That way, you get a lifetime email address, and you can keep ahead of spam.
Configure the From: header in your email program to your normal email address i.e.
[email protected] (some ISPs like Freeserve did not allow this, which is really sh*t but there are few if any of those today).
The other really great thing about the above is this:
Let's say you sign up with Ebay. For them, use an address like
[email protected]
and for Paypal, use
[email protected]
Then if you get a phishing scam from somebody pretending to be Paypal, addressed to anything other than
[email protected] you know right away it is scam.
Spam filters don't work. Loads of people write emails in a manner which causes it to be misclassified as spam. Loads of people get blacklisted; this can happen in various ways (even a whole ISP can get blacklisted) and once e.g. spamcop blacklists you you are stuffed because lots of people will suddenly never see your emails. Lots of email vanishes due to this.