hotmail Set as Default email.

You probably want to take a look at Webmailer.

Hello!
I really suggest you to use this:

http://www.macupdate.com/info.php/id/10842

It's called HttpMail PlugIn. It will let you receive, send, and manage your Hotmail account from Mail.app.
This will let you use Mail as your default email program but with your Hotmail account.
I have been using it under Tiger and Leopard. It worked fine! No bugs up to date. There is a read-me file inside, for instructions.

You may get more responses to the question over in the Mail & Address Book - Tiger Forums where the Mail users hang out.

BTW: Have you checked Safari's Preferences to determine if Mail is set up as your default email program?

As far as I know this is the only way to get around it.

AFAIK, there is no option in any of the browsers to do something similar.

I really like it, the advantage is that you can read your mail (once that has been download) offline, also you can manage all of your mail from one place. And most importantly is fully compatible with tiger/leopard if you have contacts in your address book you can easily send e-mails to them.

I use Thunderbird which is not web based like Hotmail. TB is my default email program & it is set up so through its preferences.
I could not find any such preferences in any of the browsers I use on making web based email default nor could I find anything in any of the web based emails I use.

Then again, Safari is not on my system & I could not find any mail plist files in my system either.

You can set the default mail application in Mail or by using RCDefaultApp.

However neither will allow you to specify a web page for accessing your web based mail. Webmailer provides that ability.