OOF works in OWA, and it also works in Outlook 2011 on our Apple clients. It does not however, work in Outlook 2007 and 2010.
I've done quite a bit of troubleshooting on this issue already. All IIS permissions are correct, there are no IE proxies interfering, autodiscover is setup correctly and working as intended. (Initially, it was not and I assumed this was the issue. Now it is and the issue continues. Confirmed both by https://www.testexchangeconnectivity.com & Test E-mail AutoConfiguration on our outlook clients)
I'm not sure what else I can do and I'm having trouble finding anymore information on this subject past those issues listed above. Any and all help would be greatly appreciated.
Thanks in advance!