Some other points to consider that makes Gmail best mail provider:
Speed and ease of Gmail is at par with yahoo and hotmail live.
Gmail offers free mail forwarding and pop-out services whereas other mail providers charge you for this facility.
Gmail, offer a much richer experience than counterparts unless Ajax is turned on.
Another cool feature is its Gtalk integration. You can chat with your friends write from Gmail window. Yahoo also has IM integration with its email service.
Gmail is preferred because of its speed, performance, labelling capacity and amazing search.
Gmail takes some time to get used to but later complex actions become spontaneous.
Gmail also offers other advantages such as mail fetching and tight integration with Google Calendar and Google docs. As anticipated, Gmail wins over all categories. Sources: Hotmail Plus. Yahoo Mail Plus. Hotmail Wiki. Yahoo Mail Wiki Gmail Wiki.
