I get the following error message:
Code:
Failure communicating with remote server. Please try again later.  (debug info)

Debug message: permission denied: Only admins may listen to other account IDs

Exception:

com.zimbra.common.soap.SoapFaultException: permission denied: Only admins may listen to other account IDs
ExceptionId:btpool0-0:http://172.16.20.4:80/service/soap/:1261150760164:d8483a747ae55861
Code:service.PERM_DENIED
	at com.zimbra.common.soap.Soap12Protocol.soapFault(Soap12Protocol.java:88)
	at com.zimbra.common.soap.SoapTransport.extractBodyElement(SoapTransport.java:266)
	at com.zimbra.common.soap.SoapTransport.parseSoapResponse(SoapTransport.java:227)
	at com.zimbra.common.soap.SoapHttpTransport.invoke(SoapHttpTransport.java:295)
	at com.zimbra.common.soap.SoapHttpTransport.invoke(SoapHttpTransport.java:230)
	at com.zimbra.common.soap.SoapTransport.invoke(SoapTransport.java:318)
	at com.zimbra.common.soap.SoapTransport.invokeWithoutSession(SoapTransport.java:305)
	at com.zimbra.cs.mailbox.OfflineMailbox.sendRequest(OfflineMailbox.java:776)
	at com.zimbra.cs.mailbox.OfflineMailbox.sendRequest(OfflineMailbox.java:740)
	at com.zimbra.cs.mailbox.OfflineMailbox.sendRequest(OfflineMailbox.java:736)
	at com.zimbra.cs.mailbox.OfflineMailbox.sendRequest(OfflineMailbox.java:732)
	at com.zimbra.cs.mailbox.OfflinePoller.createWaitset(OfflinePoller.java:93)
	at com.zimbra.cs.mailbox.OfflinePoller.runPoll(OfflinePoller.java:73)
	at com.zimbra.cs.mailbox.OfflinePoller.run(OfflinePoller.java:66)
	at java.lang.Thread.run(Unknown Source)

If issue persists please post description and debug information here.
I'm running the Open Source edition, version 6.0.3

The system has been running fine for the last 2 weeks now, and this afternoon this problem started...

Is there anything I need to check or do?
I already tried restarting the zimbra service through
Code:
/etc/init.d/zimbra restart
which didn't resolve the issue...

Thanks for the help and info!