Like Weeal, I'm confused. Your question ask abouts e-mail providers but everyone seems to be discussing e-mail clients.
If you're looking for a decent e-mail provider, I recommend Gawab. It's simple, free and ad-free. You can use it through a client (such as Outlook Express or Thunderbird) or via web access. There's no limit to the number of e-mail addresses which you can sign up for. For details, see paragraph 3 et seq, here:
http://www.theanswerbank.co.uk/Technology/Inte rnet/Question407429.html
I gave up on both Yahoo mail and Hotmail years ago. Both are unreliable.
GMail is popular with many people but you have to put up with the advertising content. Also, many organisations have expressed concern about the way that GMail scans all mail:
http://www.privacyrights.org/ar/GmailLetter.ht m
Chris