Hello,
im trying to add my IMAP-Email-Account (hostedt by Strato.de) to Zimbra Desktop.

But there occures an Error-Message: "Fehler bei der Kommunikation mit dem Server. Bitte versuchen Sie es später erneut."

Is anybody able to help me?

Code:
	Debugging-Nachricht: Connection is closed

Ausnahme:

com.zimbra.common.service.ServiceException: system failure: Folder sync failed
ExceptionId:sync-mbox-my@domain.de:1289986472156:b177918c4849a1db
Code:service.FAILURE
	at com.zimbra.common.service.ServiceException.FAILURE(ServiceException.java:248)
	at com.zimbra.cs.datasource.imap.ImapSync.importData(ImapSync.java:162)
	at com.zimbra.cs.datasource.imap.ImapSync.importData(ImapSync.java:129)
	at com.zimbra.cs.offline.OfflineImport.importData(OfflineImport.java:94)
	at com.zimbra.cs.datasource.DataSourceManager.importData(DataSourceManager.java:254)
	at com.zimbra.cs.datasource.DataSourceManager.importData(DataSourceManager.java:219)
	at com.zimbra.cs.mailbox.DataSourceMailbox.syncAllLocalDataSources(DataSourceMailbox.java:430)
	at com.zimbra.cs.mailbox.DataSourceMailbox.sync(DataSourceMailbox.java:460)
	at com.zimbra.cs.mailbox.DataSourceMailbox.syncOnTimer(DataSourceMailbox.java:397)
	at com.zimbra.cs.mailbox.SyncMailbox$1.run(SyncMailbox.java:262)
	at java.util.TimerThread.mainLoop(Unknown Source)
	at java.util.TimerThread.run(Unknown Source)
Caused by: com.zimbra.common.service.ServiceException: system failure: Synchronization of folder 'Sent Items' failed
ExceptionId:sync-mbox-my@domain.de:1289986472156:b177918c4849a1db
Code:service.FAILURE
	at com.zimbra.common.service.ServiceException.FAILURE(ServiceException.java:248)
	at com.zimbra.cs.datasource.imap.ImapSync.syncFailed(ImapSync.java:360)
	at com.zimbra.cs.datasource.imap.ImapSync.syncRemoteFolders(ImapSync.java:263)
	at com.zimbra.cs.datasource.imap.ImapSync.syncFolders(ImapSync.java:230)
	at com.zimbra.cs.datasource.imap.ImapSync.importData(ImapSync.java:157)
	... 10 more
Caused by: java.io.IOException: Connection is closed
	at com.zimbra.cs.mailclient.imap.ImapConnection.sendRequest(ImapConnection.java:502)
	at com.zimbra.cs.mailclient.imap.ImapRequest.send(ImapRequest.java:96)
	at com.zimbra.cs.mailclient.imap.ImapRequest.sendCheckStatus(ImapRequest.java:112)
	at com.zimbra.cs.mailclient.imap.ImapConnection.status(ImapConnection.java:277)
	at com.zimbra.cs.datasource.imap.RemoteFolder.status(RemoteFolder.java:197)
	at com.zimbra.cs.datasource.imap.ImapFolderSync.createLocalFolder(ImapFolderSync.java:480)
	at com.zimbra.cs.datasource.imap.ImapFolderSync.syncFolder(ImapFolderSync.java:123)
	at com.zimbra.cs.datasource.imap.ImapSync.syncRemoteFolders(ImapSync.java:258)
	... 12 more