We are successfully up and running with the Open Source version. We are running into a few admin interface issues that look like they will be very problematic in the future.

-- account managemant --
We host about 1100 domains. The search is nice although not perfect. I would really like to have a tab (or something) when I go into a domain (under Domains) that would show me the users and aliases for that particular domain.

-- new accounts --
When adding new accounts, there is a dropdown with the domains listed. Forst the domains arent in alphabetical order. Second, with 1100 domains, I can see that becoming a long, unmanagable list. I would prefer a text field so we could just type the domain for the email address. Also, i think the full domain list in that dropdown will eventually fall past teh bottom of the screen making many of the domains unselectable (see aliases below).

-- aliases --
In the admin interface, when you're adding aliases to an account, after you get past about 10 or 11 aliases, the domain list dropdown falls off the bottom of the screen and you cant select anything. I would prefer to have a text field like the Forwards section has.

-- administratively check email --
Since we cant see the users passwords in teh Zimbra admin, the "View Email" button doesnt do me too much good. To see someones email, I would have to usually reset their password and acces the webmail. There are definitely times that I would need to log into a users mailbox and it would be nice to be able to easily do that.

-- client interface --
In the Zimbra client webmail interface (not the admin), there should really be a button for 'Check Mail', I know that the mail flows into the inbox by itself and that you can click on the Inbox to refresh it, while showing the product to end users, thats one of the first things they have been asking me. I've had a few that have tried to refresh the page to check mail again.