We are currently trying to evaluate the possibility of using Zimbra in the following manner:

- Zimbra box acts as workgroup server
- Zimbra box integrates with existing IMAP servers
- The web client, in a webmail context, retrieves all e-mails at server mail.domain, and authenticates user via imap login.
- Zimbra does not host any e-mail or provides any POP3/IMAP service, nor provides any filtering, as it is not MX for anything.

So basically, we want it to provide groupware/webmail, on top of existing e-mail structure.

Can this be achieved? Or is Zimbra completely dependant on it's own mail services?

We are currently also looking at another solution (Atmail, www.atmail.com), which we already know provides all that I mentioned.

Thank you,