Glen's Exchange and Office 365 Dev Blog

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 ...

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...

For an updated article on this problem please have a read of https://glenscales.substack.com/p/application-is-over-its-mailboxconcurrency 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...

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...

For the last couple of years the most constantly popular post by number of views on this blog has been  Export calendar Items to a CSV file using EWS and Powershell closely followed by the contact exports scripts. It goes to show this is just a perennial issue that exists around Mail servers, I think the first VBS script I wrote to do this type of thing was late 90's against Exchange 5.5 using cdo 1.2. Now it's 2020 and if your running Office365 you should really be using the Microsoft Graph API to do this. So what I've done is create a PowerShell Module (and I made it a one file script for those that are more comfortable with that format) that's a port of the EWS script above that is so popular. This script uses the ADAL library for Modern Authentication (which if you grab the library from the PowerShell gallery will come down with the module). Most EWS properties map one to one with the Graph and the Graph actually provides better information on recurrences then...

Last July Microsoft announced here they would be disabling basic authentication in EWS on October 13 2020 which is now a little over a year away. Given the amount of time that has passed since the announcement any line of business applications or third party applications that you use that had been using Basic authentication should have been modified or upgraded to support using oAuth. If this isn't the case the time to take action is now. When you need to migrate a .NET app or script you have using EWS and basic Authentication you have two Authentication libraries you can choose from ADAL - Azure AD Authentication Library (uses the v1 Azure AD Endpoint) MSAL - Microsoft Authentication Library (uses the v2 Microsoft Identity Platform Endpoint) the most common library you will come across in use is the ADAL libraries because its been around the longest, has good support across a number of languages and allows complex authentications scenarios with support for SAML etc. The ...

The Azure AD business-to-business (B2B) platform is the underlying tech that drives both guest access in Microsoft Teams,Office365 Groups and also other Azure resources. If your someone who collaborates across a number of different organization or potentially different Community or even school or university groups you might find your MSA or Office365 account starts to accumulate Guest access to different tenants. Depending on what type of access your accruing eg If it just Microsoft Teams access you will see your guest tenancies when logging on to Teams, another way is if you logon to the Azure Portal and hit switch directory you will get a list of Azure Directories your account has an association with.  However and easier way of doing this is using PowerShell along with the ADAL, Azure Resource Management and Graph API's. I put together the following script that uses first the Azure Resource Management API to make a request that gets all the Tenants associated wi...

I've had some time recently to do some much needed updates to my Exch-Rest module so it now supports both Azure Cloud Shell and PowerShell Core on Linux (tested on RHEL,CentOS, Debian and Ubuntu). So now you can logon to an Office365 Mailbox using this Module with Powershell on Linux and send Email or a Skype for Business Message or do some mailbox reporting eg The requirements on Linux is you need to be using the latest version of PowerShell core installed as per  https://docs.microsoft.com/en-us/powershell/scripting/setup/installing-powershell-core-on-linux?view=powershell-6 .This ensures that all the required .net Core libraries will be available as older version of .Net core didn't have some of the libraries I'm using and I didn't want to backport for older versions.  Also because there are no Linux forms to interact with for authentication you need to pass in the credentials to use via a PSCredential and the code will use the password grant to get the Token e...

Folder Item numbers, size's and Attachment Item Numbers, types and sizes are one of the Mailbox statistics that is useful when your trying to look at how and why a mailbox is growing or why your mailbox performance might be declining if you have a large number of folder items. With the recent increases in Mailbox size quotas  in Office365 it can be easy to become quite indifferent to how quickly your mailbox might be growing. For example if you have 100GB quota the lazy mindset (which I admit to being a part of) can be to just keep everything you get via mail (or stack it and rack it). If your users are not able to take advantage of cloudy attachments (or the users refuse to change their use habits) the nature of expanding file sizes means a sharper growth curve for Folder Items and Attachments. The traditional way of tracking Mailbox sizes is to use Get-MailboxStatistics and Get-MailboxFolderStatistics for which there are many good scripts around that give a good overview of wha...