Install the program and then the first time, run autosizer from your
programs menu.
Get any windows open that you want to always be auto maximized.
For example, if you want your new and reply messages to be auto maximized,
create a new message and just leave it open.
Then bring up your system tray dialog and enter on autosizer.
Hit enter on open on the context menu to bring up autosizer.
You will have a list of all your currently open windows.
If you want one to be auto maximized, press alt A.
This will bring up a dialog, just hit enter.
That should have added that window class to what will be auto maximized, so
just press alt f4 when you are done adding windows from the list.
Another thing though you will want to do is bring auto sizer back up from
the system tray and press alt O for the options.
Check the checkbox that says load autosizer every time windows starts.