I'm an admin user on my ZCS v7.1.1 installation. I can view end-user mailboxes via the admin web interface. However, I want to be able to do that with arbitrary, 'external' imap clients (i.e. something other than the ZCS web interface).
Some imap servers allow you to interact with one user's mailbox, while authenticating as another user who has admin rights. I believe ZCS's imap server is like that too, as I can do so via the imapsync program via the --authuser argument. However, I can't figure out how to do so with either mutt or Thunderbird.
For example, with the UW imapd server, I can access jsmith's mailbox by authenticating as user jsmith*adminuser , where 'adminuser' is the username of an adminstrator account. I've done so via mutt and Thunderbird. However, the same trick does not work against ZCS's imap service.