Can you force outlook to use a different default mail template?

On the Home tab, in the New group, click New E-mail.
In the message body, enter the content that you want.
In the message window, click the File tab.
Click Save As.
In the Save As dialog box, in the Save as type list, click Outlook Template.
In the File name box, type a name for your template, and then click Save. (c:\users\username\appdata\roaming\microsoft\templates)

This link explain it all.

We are familiar with creating a template, and have even created a new form, with an extra field under the subject field.  We would however like this to come up as the default form for outlook, for example when you hit new email, this custom for is what always appears.

Well if you have saved template, all you can do is , pin outlook in windows toolbar, then open the location where template is and drag it to outlook in toolbar. You will have a short cut to open that template.

Other than this I will have to explore some thing from VBA.

Yeah still not exactly what we are looking for.  Thanks for the effort.

Im beginning to think there is not a way to change the default email template to a custom form we have created in outlook.

Ive stumbled across a few methods of adding a macro to the toolbar, and coding the macro to open the form.  However I dont think custom fields will be shown if doing it this way.

Using other resources we figured out how to make a new email button that looks similar to the old one, and add a macro to it.  This allowed the opening of the form as close to the default method as possible.