I am confused because the requirements you describe are exactly what the Mapiex object provides. For the MapieX interface to work Outlook does need to be installed but does not need to be actually running.
So, create mulitple profiles in the Control Room Mail dialog, set up the relevent email account you want to use in each profile. Then, just use the MAPIEX interface without having outlook running at all - using the Profile input parameters.
If you have any performance issues with mapiex (using one or more profiles) there is an article on the knowedgebase with some tips - I specifically recommend playing around with the cache email setting.