I have a trouble ticket and several conversations so far on VM eMail labeling and up until 9-1-10 (since 10/3/08ish) and possibly shortly after, my VM eMails had proper and full CID, if not CCID on them. Sometime after that date, there's a gap between then and 2-23-11 when I show them saved again, I started getting the phone number in there twice and no CID/CCID. So it did have CID/CCID in there at one time on eMails and I remember having it going out in the "early days". I know this from no complaints of people not answering because they don't know who's calling, as I get now.
I show many eMails when I was with ViaTalk that have extended CID on them. So . . .