Test-ActiveSyncConnectivity - The remote server returned an error: (403) Forbidden

Today I troubleshoot an issue where the test-activesyncconnectivity didn't work.
The following error was given when running the test:

PS] C:\Windows\system32>Test-ActiveSyncConnectivity
CasServer LocalSite Scenario Result Latency(MS) Error
--------- --------- -------- ------ ----------- -----
CASServer Default-Fi... Options Success 15.60
CASServer Default-Fi... FolderSync Failure [System.Net.WebExcept...

With the | FL we can see a more specific error message:

RunspaceId : 64768a1f-b8cc-49cd-bd76-ee70de43c728
LocalSite : Default-First-Site-Name
SecureAccess : True
VirtualDirectoryName :
Url :
UrlType : Unknown
Port : 0
ConnectionType : Plaintext
ClientAccessServerShortName : CASSERVER
LocalSiteShortName : Default-First-Site-Name
ClientAccessServer : CASSERVER.FQDN
Scenario : FolderSync
ScenarioDescription : Issue a FolderSync command to retrieve the folder hierarchy.
PerformanceCounterName : DirectPush Latency
Result : Failure
Error : [System.Net.WebException]: The remote server returned an error: (403) Forbidden.


HTTP response headers:


MS-Server-ActiveSync: 14.0
Content-Length: 5355
Cache-Control: private
Content-Type: text/html; charset=utf-8
Date: Wed, 26 May 2010 13:50:19 GMT
Server: Microsoft-IIS/7.5
X-AspNet-Version: 2.0.50727
X-Powered-By: ASP.NET


UserName : extest_3650257c296a4
StartTime : 26.05.2010 15:50:20
Latency : -00:00:01
EventType : Error
LatencyInMillisecondsString :
Identity :
IsValid : True

The reason for this is becase the default ActiveSync Mailbox Policy has been changed and does not support non- provisionable devices.

Solution is to create a new ActiveSync mailbox policy which allow non-provisionable devices and assign this to the extest_3650257c296a4 user.