In looking through the forums I see that most admins are migrating from machines that they have physical and/or admin access to or most of their current users are using one form of Outlook to access their messages. I see that migration or importing under these circumstances is fairly straight forward using the tools and importers supplied by the Zimbra team.
My company currently uses e-mail supplied from a vendor running Exchange 2007. Only a handful of my users use Outlook or Outlook Express (via POP3) to access their mail. Importing these should be no problem. All the rest use Outlook Web Access and therefore there is no .pst file to import for them.
What are my options since I don't have access of any type to the Exchange server? I'm not sure how much help the Exchange admin will be since I'm taking more than a few dollars from his pocket!
Sorry for both the length of the post and the noob question but I have not seen this scenario in the forums.

Thanks in advance for any information... It's more than I had to start with!