We recently migrated from Exchange 2003 to Exchange 2010 and were having issues with out of office.
OOF works fine in outlook but when you try and run it from OWA we get internal server error 500. The OOF URL was pointing to the internal machine and we changed this to the outside and I can access it.
I saw something about rebuilding ECP but I don't know what this actually does so I haven't tried it yet.
Any help would be apperciated