Glen's Exchange and Office 365 Dev Blog

  If you are doing any archiving, clean-up or just searching for Messages that are older then a specific date you will need to make use of a filter on the receivedDateTime. The receivedDateTime property This property represents when the Message was received expressed and stored in UTC time, this means when you query it you should also make sure your query value is in UTC. So for instance if I where looking for all the Email in the JunkEmail folder older then 30 days I could use /v1.0/users('gscales@datarumble.com')/MailFolders('JunkEmail')/messages?$Top=10&$filter=receivedDateTime lt 2020-10-21T00:00:00Z If the mailboxes are in a TimeZone other then UTC then first convert the actual date to the local date you want to include to UTC eg in Powershell something like (Get-Date).adddays(-30).Date.ToUniversalTime().ToString("o") This means if my timezone is +11 UTC my actual query time would look like 2020-10-20T13:00:00.0000000Z based on an Actual day value of ...

Mailbox analytics is something Microsoft have been working on for a number of years and its seems to be something that has received a little more effort in these pandemic times. If you have ever looked at the Non_IPM_Subtree of your mailbox you will see a lot of data being stored in their from various apps and substrate processes. A while back i wrote a ChangeDiscovery script to allow me to dump out quick what changes where happening in a Mailbox in a short time frame (eg i wanted to see what happened to all the items in a Mailbox when i performed a specific task). If you run this script with a slightly longer time-frame (eg looking over a day) it picks up all the Items that are being written and created for the Mailbox insights processes and other substrate processes. Most of these emails get written under the  Usually if I then wanted to look at these type of items I would use OutlookSpy or MFCMapi to browse the raw MAPI properties on items to see if they where of interest. Given...

One of the email UI features that I find the most useful in Outlook on the Web and Outlook mobile is the People favorites feature which saves having to do a search for historical email from particular high use contacts. Favorites is a feature that has evolved especially in Outlook on the web and Outlook mobile eg People/Persona favorites and category favorites. The way this is implemented in the Mailbox is interesting eg   People/Persona favorites get their own search folder under the favoritePersonas Folder in the Non_IPM_Subtree in a Mailbox eg As well as a configuration object under the  \ApplicationDataRoot\32d4b5e5-7d33-4e7f-b073-f8cffbbb47a1\outlookfavorites eg The configuration object is of interest as this tells as a lot about what type of favorites are being created and used in a Mailbox. It also can serve in a custom app if you want to reproduce the same type of favorites folder tree (you will need to use EWS for this as the Graph API is unfortunately hamstrung ...

As the information on how to do this would cover multiple posts, I've bound this into a series of mini post docs in my GitHub Repo to try and make this subject a little easier to understand and hopefully navigate for most people.   The Binder index is  https://gscales.github.io/Graph-Powershell-101-Binder/   The topics covered are How you can access the Recoverable Items Folders (and get the size of these folders)  How you can access and search for items in the Deletions and Purges Folders and also how you can Export an item to an Eml from that folder How you can Restore a Deleted Item back to the folder it was deleted from (using the Last Active Parent FolderId) and the sample script is located  https://github.com/gscales/Powershell-Scripts/blob/master/Graph101/Dumpster.ps1

Searching on the Categories property of an Email can pose a challenge because this property is a Multi-valued String property (which aren't that common in email) eg in a Message the property may look like the following So this needs to be queried in a different way then a normal String or single valued property in an Email would, where you could use a number of filter options (eg equal, contains,startswith). In EWS it was only possible to query this property using AQS because of the way SearchFilters translated to the underlying ROP based restrictions used by the Exchange Mailbox Store. In the Microsoft Graph the Linq format in Filters does translate more favourably so can be used eg the following simple query can find Messages in a folder based on a specific category https://graph.microsoft.com/v1.0/me/messages?filter=Categories/any(a:a+eq+'Green+Category') you can create a SearchFolder based on this query which would search all folder in a Mailbox which would produce...

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...

A while ago I published this blog post about doing this using EWS and a few people have recently asked if it is also possible to do this with the Graph API(which it is) so I've decided to include this one in my Graph Basics series. Moderation Moderation is an Exchange feature that was introduced in Exchange 2010 that allows the Human control of mail flow to a distribution group or mailbox see  https://docs.microsoft.com/en-us/exchange/security-and-compliance/mail-flow-rules/manage-message-approval  for more detail. Moderation Approve/Reject Messages When a Message is requiring moderation an email is sent to one (or more) moderators requesting approval. In the Graph you can get these moderation messages by filtering on the MessageClass property. Because this isn't a first-class property like it was in EWS you need to use the singleValueExtendedProperties representation of the property. eg in the Graph a Request like this https : //graph.microsoft.com/v1.0/me/mailFolders('I...

As well as EWS and Remote PowerShell (RPS) other mail protocols POP3, IMAP and SMTP have had OAuth authentication enabled in Exchange Online (Official announcement here ). A while ago I created  this script that used Opportunistic TLS to perform a Telnet style test against a SMTP server using SMTP AUTH. Now that oAuth authentication has been enabled in office365 I've updated this script to be able to use oAuth instead of SMTP Auth to test against Office365. I've also included a function to actually send a Message. Token Acquisition  To Send a Mail using oAuth you first need to get an Access token from Azure AD there are plenty of ways of doing this in PowerShell. You could use a library like MSAL or ADAL (just google your favoured method) or use a library less approach which I've included with this script . Whatever way you do this you need to make sure that your application registration  https://docs.microsoft.com/en-us/azure/active-directory/develop/quickstart-re...

This is part 2 of my Graph Basic's series and this post is born out of an actual need that I had over the last week which was to get a user photo from the Microsoft Graph and save it as a custom size and different image type. Like many things there are multiple ways of doing this but the Microsoft Graph GetPhoto endpoint  is pretty straight forward and delivers the image in one of the following formats 48x48, 64x64, 96x96, 120x120, 240x240, 360x360, 432x432, 504x504, and 648x648. Because I wanted to use the photo on a Elgato stream deck  this required the size be 72x72 so I needed some extra code to do the resize of the photo and change the format from a jpeg to png. Getting the user-photo from the Microsoft Graph  Before you can get the user's photo from Microsoft Graph you need to make sure the application registration you are using has one of the following permissions User.Read, User.ReadBasic.All, User.Read.All, User.ReadWrite, User.ReadWrite.All Then after you have o...

While not as popular these days many .net developers may have in the past used Managed code to run Exchange Online PowerShell cmdlets to do things like assign Mailbox Permissions or run other EXO PowerShell Cmdlets to get reporting information where no other alternatives where available (or are still available). The majority of these code bases are most likely using basic authentication using something like Or maybe some of the examples in  https://docs.microsoft.com/en-us/exchange/client-developer/management/how-to-get-a-list-of-mail-users-by-using-the-exchange-management-shell In this post I'm going to cover how to change your existing code, you might want to consider however making use of some of the new ExchangeV2 Powershell module functionality to improve performance and security . But to migrate existing code to use oAuth from Basic Authentication is relatively straight forward You will need some code to do the Authentication, for this I'm going to use the MSAL library ...

MFA (Multi Factor Authentication) is great at making the Authentication process more secure in Exchange Online but can be challenging in Automation scenarios. I originally wrote this code for something that I wanted to run unattended on a RasberryPi that was running PowerShell that i wanted to use MFA on and where i wanted to avoid going down the path of using the 90 day RefreshToken/device code method and I also didn't want to use App Authentication via Certificates or Client Secrets. Interestingly while i was writing this post Microsoft just announced Certificate based Modern Auth in Exchange Online PowerShell  https://techcommunity.microsoft.com/t5/exchange-team-blog/modern-auth-and-unattended-scripts-in-exchange-online-powershell/ba-p/1497387   .  This article also links to the Secure App Model  https://docs.microsoft.com/en-us/powershell/partnercenter/multi-factor-auth?view=partnercenterps-3.0#exchange  which is the way Microsoft are recommending you handle...

This is a follow-on from my last post on  Modifying your EWS Managed API code to use Hybrid Modern Authentication against OnPrem Mailboxes  . If instead of the EWS Managed API you are using EWS Proxy Code (generated from the EWS WSDL) and you want to migrate it to using Modern Authentication for Office365 and/or Hybrid here's a method you can use using the MSAL Authentication library . Unlike the EWS Managed API the WSDL generated proxy classes and specifically the ExchangeServiceBinding class doesn't have any provision to use Token Credentials. One way of implementing this in .NET is to take advantage of  Polymorphism and create a new class that is derived from the ExchangeServiceBinding class and then override the method GetWebResponse from this class (which is actually derived from the SoapHttpClientProtocol class which contains the actual method we are going to override  https://docs.microsoft.com/en-us/dotnet/api/system.web.services.protocols.soap...

In this post I'm going to look at what you need to do in your EWS Managed API code to support using Hybrid Modern Authentication where previously you've been using Basic or Integrated Authentication (both of which are susceptible to password spray attacks). If you don't know what  Hybrid Modern Authentication   is put simply it brings to Exchange OnPrem email clients the security benefits of Modern Authentication offered by Azure AD to Office365 tenants. If your already using OAuth to connect to Office365 you have most of the work already done but you will still need logic to ensure you have the correct Audience set in your token when that code is used against an OnPrem Mailbox.  Prerequisites  You need to be using Hybrid Exchange or more specifically  Hybrid Office 365 tenant is configured in full hybrid configuration using Exchange Classic Hybrid Topology mode ref  https://docs.microsoft.com/en-us/exchange/clients/outlook-for-ios-and-android/use-hybr...

I haven't done a basics series for a while but based on some of the questions I've been getting lately and the lack of some good Mailbox specific examples for basic but more complex tasks using the Graph against Exchange Online Mailboxes this seemed like a good series to write. For all the scripts in this series I'm not going to use any modules or other libraries so everything will be using Invoke-WebRequest and Invoke-RestMethod, while there is nothing wrong with using libraries or modules and a number of advantages in doing so it just keeps the examples as simple and easy to understand as they can be. Authentication  You can't have an article on the Graph without talking about authentication and we are now far from the past where all you needed was a simple username and password and you where off to the races. The basics of Authentication are is that first you will need an Azure App Registration (that has been consented to), there are many pages dedicated to how you c...