Exchange 2010 Impersonation trouble when requesting a User's Calendar Availability Details - calendar

Question

I'm working on project where an external application is trying to get the availability info (Free/busy) along with the details (Location/Subject/etc) for group of users in Exchange 2010.
I've read enough that I think that the best way to do this is through a service account run by the application that impersonates the user in question and pulls back their calendar information.
I've set up impersonation for the service account and run the basic test that I found on technet: http://msdn.microsoft.com/en-us/library/bb204088(v=exchg.140).aspx
This works for pulling back the mailbox folder (as the example) and if try to pull back the calendar folder.
I also found how to get availability via technet:
http://msdn.microsoft.com/en-us/library/aa563800(v=exchg.140).aspx
which will also work if I login as the user that I'm trying to find the calendar info for.
The problem comes when I try to combine both the impersonation XML with the get availability. Here is what I have for the two combine:
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
<soap:Header>
<t:ExchangeImpersonation>
<t:ConnectingSID>
<t:PrincipalName>[usersname#myorg.org]</t:PrincipalName>
</t:ConnectingSID>
</t:ExchangeImpersonation>
</soap:Header>
<soap:Body>
<GetUserAvailabilityRequest xmlns="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
<t:TimeZone xmlns="http://schemas.microsoft.com/exchange/services/2006/types">
<Bias>300</Bias>
<StandardTime>
<Bias>0</Bias>
<Time>02:00:00</Time>
<DayOrder>1</DayOrder>
<Month>11</Month>
<DayOfWeek>Sunday</DayOfWeek>
</StandardTime>
<DaylightTime>
<Bias>-60</Bias>
<Time>02:00:00</Time>
<DayOrder>2</DayOrder>
<Month>3</Month>
<DayOfWeek>Sunday</DayOfWeek>
</DaylightTime>
</t:TimeZone>
<MailboxDataArray>
<t:MailboxData>
<t:Email>
<t:Address>[usersname#myorg.org]</t:Address>
</t:Email>
<t:AttendeeType>Required</t:AttendeeType>
<t:ExcludeConflicts>false</t:ExcludeConflicts>
</t:MailboxData>
</MailboxDataArray>
<t:FreeBusyViewOptions>
<t:TimeWindow>
<t:StartTime>2011-07-28T00:00:00</t:StartTime>
<t:EndTime>2011-07-28T23:59:59</t:EndTime>
</t:TimeWindow>
<t:MergedFreeBusyIntervalInMinutes>5</t:MergedFreeBusyIntervalInMinutes>
<t:RequestedView>DetailedMerged</t:RequestedView>
</t:FreeBusyViewOptions>
</GetUserAvailabilityRequest>
</soap:Body>
</soap:Envelope>
What I get back is this:
<?xml version="1.0" encoding="utf-8"?>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Body>
<s:Fault>
<faultcode xmlns:a="http://schemas.microsoft.com/exchange/services/2006/types">a:ErrorProxyRequestNotAllowed</faultcode>
<faultstring xml:lang="en-US">Client context header found but no request type found in SOAP header.</faultstring>
<detail>
<m:ErrorCode xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages">5015</m:ErrorCode>
</detail>
</s:Fault>
</s:Body>
</s:Envelope>
Digging around a little more in technet, the ErrorProxyRequestNotAllowed info:
"This error indicates that the request that Exchange Web Services sent to another Client Access server when trying to fulfill a GetUserAvailability request was invalid. This response code typically indicates that a configuration or rights error has occurred, or that someone tried unsuccessfully to mimic an availability proxy request."
What I'm having trouble with, is how impersonation seems to be working in the cases where I'm pulling back the user's mail and calendar folders, but not working for the case where I want to check their availability.
Right now, I'm just sending the straight XML via curl (wrapped in a little python script).
Anyone have any pointers? Thanks in advance!

Answer 1

I finally found a few (old) references that this is known feature/bug with GetUser[blank]Request style calls and Impersonation.
The two just do not work together. I hope this save someone a little time.