I called a co-worker whose Connection 8.5(1)SU2 mailbox was full. I recieved an e-mail indicating that his voice mailbox is full (we use Single Inbox/EWS Exchange 2007SP1), then my voicemail light on my Cisco phone illuminated and it indicated that I had one new voice message available. No one actually left me a message.
Why did the MWI light turn on when I got the NDR?