Ability to create redirects to external sites or other domains of the current site.
Ability to create redirects from URL's that contain file extension (.asp, .php, etc.) but not .htm and .html
If you want to setup a redirect from "/some/url.htm" to any other, just create a new URL redirect using "/some/url" (excluding ".htm" extension) in FROM field. Such setup will cause a redirect either from "/some/url" or "/some/url.htm" or "/some/url.html".