This exact http URL is then sent to the users BackEnd Server
OMA sends the URL built to the BE server, in our case http://BE/Exchange/Administrator/
The URL sent by OMA “http://BE/Exchange/Administrator/” is then picked up by Davex.dll as an EXPLICIT OWA request. See KB812220 for more info.
OMA will FAIL if SSL is REQUIRED on the exchange virtual directories it tries to access, with our without FBA enabled.
OMA will work with Forms Based Authentication as OMA does NOT need Integrated Authentication/Kerberos.
If the Exchange Virtual directory is set to require SSL then you must create an Alternate Exchange Virtual directory for OMA to use and NOT require SSL on that Virtual directory. See KB817379 for more on that!