Trying out Zimbra desktop (build 1083) for the first time.

Had no problem setting up my gmail account, but can't succesfully set IMAP with our internal e-mail server ( on an apple server).
During the account setup it fails authentication (system failure: Error authenticating ), but it seems for an odd reason based on a simple message on the server.
Thunderbird and outlook authenticate without problem.

On the Apple server system log, the only difference we can see is that with Outlook and Thunderbird we see "... plaintext User" and with Zimbra we see "...plain user" in the authentication process.

Any light you could shed on this would be appreciated. Let me know what other info you may need. I would really like to give the Zimbra desktop a spin as my main mail/calendering client.

Thanks,
MarKG

Below are the mailbox.log lines of the last attempt:

2008-03-18 15:53:13,864 INFO [btpool0-39] [name=zimbra;ip=127.0.0.1;] datasource - Testing DataSource: { id=ae12edb2-a347-48ef-a161-f24dddf0b2cd, type=imap, isEnabled=true, name=Polytop Corp, host=192.168.111.2, port=143, connectionType=cleartext, username=mgrabowski, folderId=1 }
2008-03-18 15:53:16,911 INFO [btpool0-39] [name=zimbra;ip=127.0.0.1;] datasource - Testing connection to data source
javax.mail.AuthenticationFailedException: Error authenticating
at com.sun.mail.imap.IMAPStore.protocolConnect(IMAPSt ore.java:553)
at javax.mail.Service.connect(Service.java:275)
at com.zimbra.cs.datasource.ImapImport.test(ImapImpor t.java:134)
at com.zimbra.cs.datasource.DataSourceManager.test(Da taSourceManager.java:71)
at com.zimbra.cs.account.offline.OfflineProvisioning. testDataSource(OfflineProvisioning.java:483)
at com.zimbra.cs.account.offline.OfflineProvisioning. createDataSourceAccount(OfflineProvisioning.java:5 01)
at com.zimbra.cs.account.offline.OfflineProvisioning. createAccount(OfflineProvisioning.java:398)
at com.zimbra.cs.service.admin.CreateAccount.handle(C reateAccount.java:58)
at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEng ine.java:347)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:213)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:118)
at com.zimbra.soap.SoapServlet.doPost(SoapServlet.jav a:272)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:727)
at com.zimbra.cs.servlet.ZimbraServlet.service(Zimbra Servlet.java:175)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(Ser vletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler.handle(Se rvletHandler.java:362)
at org.mortbay.jetty.security.SecurityHandler.handle( SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(Se ssionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(Co ntextHandler.java:716)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebA ppContext.java:406)
at org.mortbay.jetty.handler.ContextHandlerCollection .handle(ContextHandlerCollection.java:211)
at org.mortbay.jetty.handler.HandlerCollection.handle (HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:139)
at org.mortbay.jetty.handler.RewriteHandler.handle(Re writeHandler.java:176)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:139)
at org.mortbay.jetty.Server.handle(Server.java:313)
at org.mortbay.jetty.HttpConnection.handleRequest(Htt pConnection.java:506)
at org.mortbay.jetty.HttpConnection$RequestHandler.co ntent(HttpConnection.java:844)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser. java:644)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpPa rser.java:211)
at org.mortbay.jetty.HttpConnection.handle(HttpConnec tion.java:381)
at org.mortbay.io.nio.SelectChannelEndPoint.run(Selec tChannelEndPoint.java:396)
at org.mortbay.thread.BoundedThreadPool$PoolThread.ru n(BoundedThreadPool.java:442)
2008-03-18 15:53:16,911 INFO [btpool0-39] [name=zimbra;ip=127.0.0.1;] datasource - Test failed: Error authenticating