There are 2 ways that Exchange Server 2007 UM is integrated with your OOF. The first is from the telephone using Outlook Voice Access (OVA) and the 2nd is from the desktop using Outlook or Outlook Web Access (OWA):
1. By using logging into OVA, you can change your telephone greeting to an Out-of-office greeting and you can also turn on your E-mail out-of-office auto-replies if you forgot to do this in Outlook or OWA.
2. By using Outlook or OWA, you can change the telephone greeting played to callers when you are out of office.
- David Fong