My draft message gets deleted from drafts when I send it?

I am doing a newsletter in html format in Outlook (2007).

Every so often I send my newsletter to test what it looks like to my gmail or hotmail address.
Trouble is, when I send it, it gets deleted from Drafts so I cannot go back in and work on it. :s

Any ideas on how I can send it out but also go back and edit it?

After you send the email it becomes a 'sent' email and is no longer considered a draft. You'll find these editable emails in "sent" items.