Skip to main content

Oneliner Mailbox access with Powershell in Exchange Online using the oData preview

One of the things that was announced at MEC recently was Microsoft's Cloud first strategy with Exchange, which basically means that new feature will appear in Exchange Online first and then at some later date make their way into the OnPremise version of Exchange. One of these new cloud first features is the OData API for Mailbox data which is a REST based API for accessing mailbox data (as apposed to EWS which is a SOAP based API for accessing mailbox data). JSON and REST have become the standard for building WebAPI's over the past few years and every man and his dog (Google, Facebook,Twitter,Apple etc) are now using this so its exciting to see Exchange make this move.

If you want to find out more about it and you have a couple of hours to watch some good video's I would check the following two presentations from MEC http://channel9.msdn.com/Events/MEC/2014/EXT301 and  http://channel9.msdn.com/Events/MEC/2014/EXT304 which will give you a good grounding in both oData  and also the new consent framework which is important if your building modern apps. 

One of the interesting things your can do with these REST API is using the Invoke-RestMethod cmdlet in Powershell v4 is now get access to Mailbox data with one line of code. Here are a few samples to wet your appetite and get you started (note this API is still in preview so this is subject to change/errors and bugs)

Show Unread Inbox Messages


  1. Invoke-RestMethod -Uri "https://outlook.office365.com/ews/odata/Me/Inbox/Messages?`$filter=IsRead eq false" -Credential (get-credential) | foreach-object{$_.value | select Subject}  

Show Calendar Appointments for the next 7 days


  1. Invoke-RestMethod -Uri ("https://outlook.office365.com/ews/odata/Me/Calendar/Events?`$filter=Start le " + (Get-Date).ToUniversalTime().AddDays(7).ToString("yyyy-MM-ddThh:mm:ssZ") + " and End ge " + (Get-Date).ToUniversalTime().ToString("yyyy-MM-ddThh:mm:ssZ")) -Credential (Get-Credential) | foreach-object{$_.Value}  

Show Contacts


  1. Invoke-RestMethod -Uri "https://outlook.office365.com/ews/odata/Me/Inbox/Messages" -Credential (get-credential) | foreach-object{$_.value}  

There are lots more example of using the new REST commands at http://msdn.microsoft.com/en-us/library/office/dn605892(v=office.15).aspx


Popular posts from this blog

The MailboxConcurrency limit and using Batching in the Microsoft Graph API

If your getting an error such as Application is over its MailboxConcurrency limit while using the Microsoft Graph API this post may help you understand why. Background   The Mailbox  concurrency limit when your using the Graph API is 4 as per https://docs.microsoft.com/en-us/graph/throttling#outlook-service-limits . This is evaluated for each app ID and mailbox combination so this means you can have different apps running under the same credentials and the poor behavior of one won't cause the other to be throttled. If you compared that to EWS you could have up to 27 concurrent connections but they are shared across all apps on a first come first served basis. Batching Batching in the Graph API is a way of combining multiple requests into a single HTTP request. Batching in the Exchange Mail API's EWS and MAPI has been around for a long time and its common, for email Apps to process large numbers of smaller items for a variety of reasons.  Batching in the Gr...

EWS-FAI Module for browsing and updating Exchange Folder Associated Items from PowerShell

Folder Associated Items are hidden Items in Exchange Mailbox folders that are commonly used to hold configuration settings for various Mailbox Clients and services that use Mailboxes. Some common examples of FAI's are Categories,OWA Signatures and WorkHours there is some more detailed documentation in the https://msdn.microsoft.com/en-us/library/cc463899(v=exchg.80).aspx protocol document. In EWS these configuration items can be accessed via the UserConfiguration operation https://msdn.microsoft.com/en-us/library/office/dd899439(v=exchg.150).aspx which will give you access to either the RoamingDictionary, XMLStream or BinaryStream data properties that holds the configuration depending on what type of FAI data is being stored. I've written a number of scripts over the years that target particular FAI's (eg this one that reads the workhours  http://gsexdev.blogspot.com.au/2015/11/finding-timezone-being-used-in-mailbox.html is a good example ) but I didn't have a gene...

Sending a MimeMessage via the Microsoft Graph using the Graph SDK, MimeKit and MSAL

One of the new features added to the Microsoft Graph recently was the ability to create and send Mime Messages (you have been able to get Message as Mime for a while). This is useful in a number of different scenarios especially when trying to create a Message with inline Images which has historically been hard to do with both the Graph and EWS (if you don't use MIME). It also opens up using SMIME for encryption and a more easy migration path for sending using SMTP in some apps. MimeKit is a great open source library for parsing and creating MIME messages so it offers a really easy solution for tackling this issue. The current documentation on Send message via MIME lacks any real sample so I've put together a quick console app that use MSAL, MIME kit and the Graph SDK to send a Message via MIME. As the current Graph SDK also doesn't support sending via MIME either there is a workaround for this in the future my guess is this will be supported.
All sample scripts and source code is provided by for illustrative purposes only. All examples are untested in different environments and therefore, I cannot guarantee or imply reliability, serviceability, or function of these programs.

All code contained herein is provided to you "AS IS" without any warranties of any kind. The implied warranties of non-infringement, merchantability and fitness for a particular purpose are expressly disclaimed.