The Apple iPhone supports the following audio formats:
AAC (16 to 320 Kbps)
AIFF
AAC Protected (MP4 from iTunes Store)
MP3 (16 to 320 Kbps)
MP3 VBR
Audible (formats 2-4)
Apple Lossless
WAV
Unfortunately, Ogg Vorbis didn't make the list.
The Apple iPhone supports the following audio formats:
AAC (16 to 320 Kbps)
AIFF
AAC Protected (MP4 from iTunes Store)
MP3 (16 to 320 Kbps)
MP3 VBR
Audible (formats 2-4)
Apple Lossless
WAV
Unfortunately, Ogg Vorbis didn't make the list.
[...] « What audio formats will the iPhone play/support? [...]
[...] What audio formats will the iPhone play/support? The Apple iPhone supports the following audio formats: AAC (16 to 320 Kbps) AIFF AAC Protected (MP4 from iTunes Store) MP3 (16 to 320 Kbps) MP3 VBR Audible (formats 2-4) Apple Lossless WAV. Unfortunately, Ogg Vorbis didn?t make the … [...]
I cannot get my iPhone to play wav files that are attached to an email. Our Cisco voicemail system sends voicemail messages as emails with an attached wav file. My iPhone will not play them.
Take a look at this link. I think the new version of software supports downloading WAV files from your Unity/Echange server.
There could also be an issue with the audio format (Codec) that Unity is set up for. If the server is using G.729 instead of G.711 the playback may not be supported.
http://theappleblog.com/2007/10/02/iphone-recognizes-audio-email-attachments/