I've never found Incredimail to be a particular business-like application, so I find yours a somewhat amazing wish.
May I suggest you contact Incredimail's VIP support, as told on http://www.incredimail.com/english/help/im/support_contact.asp?id=95682
"VIP Support is a technical support service available only to IncrediMail Premium members. Our VIP Support team is dedicated to help you on a personal basis with any problems or issues you experience with IncrediMail."
That seems to be what you need.
But I don't consider it a promising sign that a search for "office live" on their help site turns up zero hits.
I recently started using Incredimail, and have been able to use it with my regular hotmail just fine. What I am having problems with is figuring out how to use it with my new email from my office live account. I now have a business website and would like to use incredimail with it. My new email does not use the hotmail extension, but uses email@example.com. Can anyone help?