I offen wondered how I can programmatically read items from mailboxes stored within Microsoft Exchange Server. Some time ago I used Outlook with some macros that accessed the information I needed. But what if Outlook does not run? Or what if the computer crashed – who would logon and start Outlook? Sure you can find workarounds for every problem. But this never seemed to be a ‘cool’ solution to me. In the past few weeks – after I got my Exchange 2010 MCITP – I started to have a look at EWS – Exchange Web Services (available since Microsoft Exchange Server 2007). This one seemed to be pretty simple and also a stable solution to all my needs. Here is how I do it all now with vbscript…
There is not much you’ll need to connect to Exchange, just a http connection to your Client Access Server, a user with credentials and access to the mailbox you want to read, a soap xml request and some lines of code that will parse the response for you.
First we need to decide what we want to do, or better: we need to create the request telling EWS what to do. In this example I want to know about every calendar item in a certain time span. But you can do much more:
- create, move, copy, delete, update, find calendar, email, folder, … items
- get user availability, get and set out of office settings
- add, remove, update delegates
- many many more, have a look at the full list at http://msdn.microsoft.com/en-us/library/bb409286(v=EXCHG.140).aspx
Since we want to crawl for many items we will use the FindItem Operation. Following this link you’ll get a complete overview how the request will look like. In common every operation that can be used with Exchange Web Service is really well documented!
A basic example of a soap request can be found at the bottom of the page: BasicEWSSoapRequest.xml.
We use this basic example and make some modifications – we want to read all properties in the calendar for example, we do want to connect to another mailbox and we do want to use a certain time span not the whole calendar. So the final soap request would look like the one in CalendarItemsFromAnotherUserEWSSoapRequest.xml.
Now we need to connect to EWS, post this request, wait for the answer and parse it. Since this is a complex xml structure we just need to break it down to that level the information is stored in – in this example it is the “t_Items” node. ReadEWS.vbs shows the code being used to all that stuff:
Documentation for functions, methods and properties used in this post: