Thursday, March 28, 2019

How to log EWS Traces to a file in PowerShell

If your using the EWS Managed API in your PowerShell scripts and you need to do some extended debugging to work out why a script isn't working the way you expect in certain environments you can do this by using Tracing as described in . What this does once it is enabled is it outputs all the requests and responses that are sent to and from the Exchange server so you can see exactly what is taking place and potentially more information on particular errors that are occurring.  So in a EWS Managed API script to enable this you just need to set the TraceEnabled property on the ExchangeService object to true eg

$server.TraceEnabled = $true

And you will then start seeing traces like the following in the console

A much cleaner way of capturing these traces is to configure the EWS Managed API to use a separate log file to log them to a file so you can review them later. To do this it requires that you create a class that implements an Interface of ITraceListener .  In C# this a pretty trivial thing to do but in PowerShell its a little more complicated. However using Add-Type in PowerShell gives you the ability to simply define your own custom class that implements the interface and then compile this on the go which then makes it available in your PS Session. The basic steps are

  • You need to define an class that implements the interface (through inheritance) and the methods defined in that interface in this case it only has one called Trace
  • Define your own code to perform the underlying logging in my example its a simple one liner that will append the Tracemessage to a File the path of which is held in the Public Property I've defined in my class 
  • Use Add-Type to compile the class and make it available in your PS Session
  • Create a Instance of the Class you just defined eg here's a function to do it
function TraceHandler(){
$sourceCode = @"
    public class ewsTraceListener : Microsoft.Exchange.WebServices.Data.ITraceListener
        public System.String LogFile {get;set;}
        public void Trace(System.String traceType, System.String traceMessage)
            System.IO.File.AppendAllText(this.LogFile, traceMessage);

    Add-Type -TypeDefinition $sourceCode -Language CSharp -ReferencedAssemblies $Script:EWSDLL
    $TraceListener = New-Object ewsTraceListener
   return $TraceListener


Then in your PS Code just use the Instance (Object) of the Class you just created (first setting the LogFile property to path of the File you want to log to) eg

        $service.TraceEnabled = $true
        $TraceHandlerObj = TraceHandler
        $TraceHandlerObj .LogFile = "c:\Tracing\$MailboxName.log"
        $service.TraceListener = $TraceHandlerObj 

Friday, March 08, 2019

Microsoft Teams Private Chat History Addin for Outlook

Being somebody who is transitioning across from Skype for Business to Teams one of things I missed the most (and found the most frustrating) is the lack of the ability in Outlook and OWA to view the conversation history from Online meetings and private chats in Microsoft Teams. This is especially frustrating when you have an external meeting and your sent an IM that contains some vital information for what you need to do. This information is tracked in your mailbox for compliance reasons in the Teams Chat folder but this folder is hidden so it not accessible to the clients and must be extracted by other means eg. Most people seem to point to doing a compliance search if you need this data .

Given that the information is in my mailbox and there shouldn't be any privacy concern around accessing it I looked at a few ways of getting access to these TeamsChat messages in OWA and Outlook the first way was using a SearchFolder. This did kind of work but because of a few quirks that the Hidden folder caused was only usable when using Outlook in online mode (which isn't very usable). The next thing I did was look a using an Addin which worked surprising well and was relatively easy to implement. Here is what it looks likes in action all you need to do is find an Email from the user you want to view the Teams chat messages from and then a query will be executed to find the last 100 Chat messages from that user using the Outlook REST endpoint eg

That constructs a query that looks like the following to Outlook REST endpoint$OrderyBy=ReceivedDateTime Desc&$Top=30&$Select=ReceivedDateTime,bodyPreview,webLink&$filter=SingleValueExtendedProperties/Any(ep: ep/PropertyId eq 'String 0x001a' and ep/Value eq 'IPM.SkypeTeams.Message') and SingleValueExtendedProperties/Any(ep: ep/PropertyId eq 'String 0x5D01' and ep/Value eq '')

To break this down a bit first this gets the first 30 messages from the AllItems Search Folder sorted by the ReceivedDateTime$OrderyBy=ReceivedDateTime desc&$Top=30
Next this selects the properties we are going to use the table to display, I used body preview because for IM's that generally don't have subjects so getting the body preview text is generally good enough to shown the whole message. But if the message is longer the link is provided which will open up in a new OWA windows using the weblink property which contains a full path to open the Item. One useful things about opening the message this way is you can then click replay and continue a message from IM in email with the body context from the IM (I know this will really erk some Teams people but i think it pretty cool and has proven useful for me).


Next this is the filter that is applied so it only returns the Teams chat messages (or those messages that have an ItemClass of IPM.SkypeTeams.Message and are from the sender associated with the Message you activate the Addin on. I used the Extended property definition for both of these because firstly there is no equivalent property and for the From address if you used orderby and the a from filter like  and from/emailAddress/address eq '' there's a bug that the messages won't sort by the date so you always get the old messages first. Using the extended property fixed that issue but its a little weird.

 $filter=SingleValueExtendedProperties/Any(ep: ep/PropertyId eq 'String 0x001a' and ep/Value eq 'IPM.SkypeTeams.Message') and and SingleValueExtendedProperties/Any(ep: ep/PropertyId eq 'String 0x5D01' and ep/Value eq '') One thing I did find after using this for a while is that it didn't work when I got a notification from teams like the following

Because the above notification message came from it couldn't be used in the above query. Looking at the notification message unfortunately there wasn't any other properties that did contain the email address but the full DisplayName of the user was used in the email's displayName so as a quick workaround for these I made use of EWS's resolvename operation to resolve the displayName to an email address and then I could use the Addin even on the notification messages to see the private chat message that was sent to me within OWA without needing to open the Teams app (which if you have teams account in  multiple tenants can be a real pain). So this one turned into a real productivity enhancer for me. (A quick note is that this will only get the Private Chat messages from the user not the Channel Messages).

Want to give it a try yourself ?

I've hosted the files on my GitHub pages so its easy to test (if you like it clone it and host it somewhere else). But all you need to do is add it as a custom addin (if your allowed to) using the

The GitHub repository for the Addin can be found here