EWS: Reading of linked calendars over WebServices -- How can i get the necessary email-adresses?

Question

What i want to do:
i'm working on an service, witch should connect to an exchange-server an get all changed appointments to store them
in an extra database.
What i already have:
I have the servnce yet done, except of one thing.
My problem:
The idea was to create a dummy-exchange-user, witch has linked all the shared calendars from oder users. So this
user can see all the shared calendars in outlook.
I can already read this linked calendars with FindItemType(), but i need the email-address of each mailbox witch
belongs to the linked calendars.
for example:
z.B.
User1 has the address [email protected]
User2 has the address [email protected]
User2 has shared his calendar and User1 has linked this shared calendar.
If i don't specify the email-address, i get all appointments auf the mailbox, witch i'm connected to 8in this
example the calendar of User1). If i specify the email-address of User2, i'll get the calendar of user2.
Here my code (i shorted it a little bit):
Private Function GetAppointmentsFromExchange(ByVal emailAdress As String, ByVal StartZeit As Date) As List(Of GroupWareAppointment)
Dim lAppointmentList As New List(Of GroupWareAppointment)
'Create new Find-Request
Dim lFindRequest As FindItemType = New FindItemType()
lFindRequest.Transversal = ItemQueryTransversalType.Shallow
lFindRequest.ItemShape = New ItemResponseShape()
lFindRequest.ItemShape.BaseShape = DefaultShapeNamesType.Default
'Specify the folder to search
Dim lCalendar As DistingishedFolderIdNameType.Calendar
lCalendar.Id = DistinguishedFolderNameType.calendar
'if not my own calendar, then specify the email-address of the linked calendar
If Not (String.IsNullOrEmpty(emailAdress)) Then
lCalendar.Mailbox = New EmailAddressType()
lCalendar.Mailbox.EmailAddress = emailAdress
End If
lFindRequest.ParentFolderIds = New BaseFolderIdType() {lCalendar}
'some nonrelevant code
'Send Request to Server
Dim lResponse As FindItemResponseType = myExchangeServerAccess.FindItem(lFindRequest)
'some nonrelevant code
Return lAppointmentList
End Function
This works pretty fine. But i have to know all the email-addresses of the linked calendars.
The problem is now, that i don't know how to get this email-addresses. I looked a lot in the internet, but it seems,
that ews doesen't have such a function.
The only solution i found was to look in the active directory. But this won't work because active directory is not
realy connected to exchange.
So i need either a list of the exchange-users (i need only the email-adresses of the connected calendars, not of all
the users on exchange) or a other solution, how i can get appointments from linked calendars without to specify the
email-adresses.
Does anybody have a tip for me?
(Sorry for my bad english)

Answer 1

Maybe somebody is interessted, how i solved it.
My solution isn't pretty, but it works.
First i get only the users, who have an mailbox on exchange from active directory.
Then i try to get their calendar in a loop. If i don't hav the permission for the calendar, i try the next user.
Getting the whole appointments with GetItem() was very slow. So i get only the ItemIDs an then get only this propertys of an appointment, witch i need (AditionalPropertys). This works faster.
His Method works, but there is a problem. I can't see, witch appointments were deleted.
So i tryed SyncFolderItem(). This wors very fine. I get the new, the changed an the deleted (not the whole appointments, because they are deleted. only the IDs).
The only problem is the Property SyncState. This property defindes, from when SyncFolderItem() should sync. But SyncState isn't a date. It looks like a ID. I recive it every time, i start SyncFolderItem().
So i have to store the recived SyncState to use it für the next sync. Otherwise the sync will start from the begining.
It's pitty, that it isn't possible to use a date also.
I thes days i will try the notofications, so that exchange notifiy me, when there is a change. I don't know, if its true, because some books tell, that otofications works only with one mailbox (the mailbox i'm connected to), an some books tell opposite.
I will try it.