[horde] Problem with ActiveSync

[robert at gmx.li]

Hi,

i am running Horde Groupware Webmail Edition 5.0.2. Had ActiveSync running without problems for some time. Suddenly it stopped working (for all users), i really don't know what could have changed on the server.

I ran a test at https://www.testexchangeconnectivity.com/, results:

Testing HTTP Authentication Methods for URL https://example.com/Microsoft-Server-ActiveSync/.
 	The HTTP authentication methods are correct.

An ActiveSync session is being attempted with the server.
Attempting to send the OPTIONS command to the server.
The OPTIONS response was successfully received and is valid.
Additional Details
 	Headers received: Pragma: no-cache
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Date: Wed, 05 Dec 2012 18:51:43 GMT
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Set-Cookie: PHPSESSID=t0tbgooo26knv7r4n25mu9rq71; path=/,horde_secret_key=t0tbgooo26knv7r4n25mu9rq71; path=/; domain=example.com; httponly,default_horde_view=auto; expires=Fri, 04-Jan-2013 18:51:44 GMT; path=/; domain=example.com
Server: Apache
X-Powered-By: PHP/5.3.3-7+squeeze14
MS-Server-ActiveSync: 6.5.7638.1
MS-ASProtocolVersions: 1.0,2.0,2.1,2.5
MS-ASProtocolCommands: Sync,SendMail,SmartForward,SmartReply,GetAttachment,GetHierarchy,CreateCollection,DeleteCollection,MoveCollection,FolderSync,FolderCreate,FolderDelete,FolderUpdate,MoveItems,GetItemEstimate,MeetingResponse,ResolveRecipients,ValidateCert,Provision,Search,Ping
Content-Length: 0
Content-Type: application/vnd.ms-sync.wbxml

Now here is the error:

Attempting the FolderSync command on the Exchange ActiveSync session.
 	The test of the FolderSync command failed.
 			Additional Details
 	No Inbox folder could be found in the XML response.

I have no idea where to start to look for the error, any ideas? I configured a  custom log $conf[activesync][logging][path] but it is empty ...

Thanks

robert