Hi SrillAlive,
Outlook was never designed to be anything other than an end user WYSIWYG editor. (What You See Is What You Get) While you can right click on HTML emails you recieve, and View the Source html, there is no "out of the box" way to compose an html email.. Outlook does it automatically for you. There are add ons availabe... but they tend to be overpriced for what you want to accomplish.
It looks like you host through
http://www.dynaserve.com ... I'm not familiar with what type of email solution they offer you or if you just resolve your mx records to point to your own server. Regardless IF you use thier email application they probably have a web interface and a way to compose email from it.
I would assume your best bet would be to start there and see if you can copy and paste your code to the web interface.
There will more than likely (hopefully to make it easy for you) a way to select the formatting of your message in thier email solution...e.g. switch from rich text to html < >
....OK now I looked up your MX record and it looks like you would log into
https://email.secureserver.net/login.php...
Start there amd see what you can accomplish.
Another option is to use a diffent application to compose and send your email or build a simple vb app and call on outlook ado's
There are a ton of free open source progs that do just this... its a matter of preference and ease.. I would recomend one but I don't use them that offten as I would just write a script now a days...
OH YEAH..... not sure what you intent is but you may want to familiarize yourself with Can-Spam Act and make sure you're compliant. Alot of people frown on un-solicited email marketing.
Hope this helps or at least gets you started in the right direction.
Regards,