It seems strange to me that Yahoo has an email service for small businesses at all. It doesn't support IMAP, and even the Zimbra Desktop client doesn't seem to work with it. Don't small business need IMAP to sync between multiple computers and mobiles? More than casual home users? I'd really like true IMAP, but I'd settle for Zimbra Desktop, but alas, it doesn't work with Yahoo Small Business Mail either. I wish Yahoo would get it together!
Any idea if/when IMAP or Zimbra support will come to Yahoo Small Business users?