How to send HTML email?

I am trying to send an HTML based email for my buisness through my yahoo account. any ideas?How to send HTML email?
Outlook Express:


1.Click on ';Tools'; and choose ';Options';


2.Switch to the ';Send'; tab


3.Make sure that the Mail sending format is ';HTML';


4.Click ';OK';


Thunderbird


1.Choose Message %26gt; New Message or Ctrl-M


2.Use the Thunderbird editor to add your HTML into your message directly


Sending HTML Email Tricks


鈥ome mail clients will let you use the %26lt;base href=';';%26gt; tag in the %26lt;head%26gt; of your HTML email, but not all email clients support that tag


鈥ackground images (in the %26lt;body%26gt; tag) only work in some email clients


鈥he bgcolor attribute works best if you put it in a table, and enclose your entire email in a single