The majority of the free services only allow you to use web-based access; you can't use an email client (such as Outlook, Outlook Express, Windows Mail or Thunderbird) with them. There are just a few services which let you use both methods of sending and receiving your mail. The most well-known is Gmail:
http://mail.google.com/
However some people don't like the way that Gmail scans all of your mail in order to append advertising:
http://www.privacyrig...rg/ar/GmailLetter.htm
My own preference is to use Gawab. For instructions on how to set up a free (and advert-free) Gawab account, including how to configure your email client to work with it, see paragraph 3 et seq of my first post here:
http://www.theanswerb...t/Question407429.html
(Ignore my later post there. It was inadvertently attached to the wrong thread).
Chris