I installed zimbra desktop about a week ago but I have never been able to get a successfull sync, it always ends in error. I either get an authentication error, a message telling me my password may have changed and I should re-validate or Zimbra just goes offline without downloading any mail. The logs sometime show a timeout error. I am currently getting the error below. I haven't seen any other similar problems, is this Zimbra or is something up with my yahoo plus account?

offline - sync remote auth failure: nickcrebbin
com.zimbra.common.service.ServiceException: system failure: Unable to connect to IMAP server: DataSource: { id=71c1ccc7-4600-4fcc-86c2-490eac28da1e, type=imap, isEnabled=true, name=nickcrebbin, host=zimbra.imap.mail.yahoo.com, port=993, connectionType=ssl, username=nickcrebbin, folderId=1 }
ExceptionId:btpool0-0:1234101201582:2d73cdbde98820b6
Code:service.FAILURE
at com.zimbra.common.service.ServiceException.FAILURE (ServiceException.java:253)
at com.zimbra.cs.datasource.ImapSync.connect(ImapSync .java:156)
at com.zimbra.cs.offline.YMailImport.connect(YMailImp ort.java:69)
at com.zimbra.cs.datasource.ImapSync.importData(ImapS ync.java:127)
at com.zimbra.cs.OfflineImapImport.importData(Offline ImapImport.java:48)
at com.zimbra.cs.offline.YMailImport.importData(YMail Import.java:90)
at com.zimbra.cs.datasource.DataSourceManager.importD ata(DataSourceManager.java:154)
at com.zimbra.cs.mailbox.LocalMailbox.importData(Loca lMailbox.java:417)
at com.zimbra.cs.mailbox.LocalMailbox.syncAllLocalDat aSources(LocalMailbox.java:389)
at com.zimbra.cs.mailbox.LocalMailbox.sync(LocalMailb ox.java:431)
at com.zimbra.cs.service.offline.OfflineSync.handle(O fflineSync.java:49)
at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEng ine.java:429)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:286)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:160)
at com.zimbra.soap.SoapServlet.doPost(SoapServlet.jav a:269)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:727)
at com.zimbra.cs.servlet.ZimbraServlet.service(Zimbra Servlet.java:190)
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)
Caused by: javax.security.auth.login.LoginException: AUTHENTICATE failure. Server Error-Please try again after some time
at com.zimbra.cs.datasource.ImapSync.connect(ImapSync .java:151)
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