I think
www.mailshell.com is the best Web based email system out there.
It allows you to setup multiple email accounts (temporary email aliases), which you can use when web-sites or services require an email. This means you can filter all junk mail and your "core" email address can be kept just for trusted friends or accounts.
You can also "associate" a personal domain with Mailshell. For example, mydomain.com. So you could have unlimited email addresses like
sales@mydomain.com,
subscriptions@mydomain.com,
webzine@mydomain.com... anything you want. You get the idea. But you still access them all via a single web interface.
Check it out. Highly recommended.
Mr Mephisto