Quick info about this app

Hi! The above application is just POC how to use MS Graph to send email in C# application base on .NET Framwork 4.8.

About repository

Clone this repository, setup conifig.app and fill be free to change code. I tried to describe all classes and methods in source for easier understand and use app. More about code is on my blog (in polish).

#1 Create Azure App and Mail-enabled security group

On first place create new Azure App on Register an application - Microsoft Azure, save application (client) ID.

Then in Manage -> API permissions add new permissions: Mail.Send as Application and grand admin consent.

Next create or use the Mail-enabled security group, and add members.

! Only these members will be able to send email from the app.

#2 Create new Application Access Policy

By using Terminal connect to Exchange Online. Run the following command, replacing the arguments for AppId, PolicyScopeGroupId, and Description:

New-ApplicationAccessPolicy -AppId e7e4dbfc-046f-4074-9b3b-2ae8f144f59b -PolicyScopeGroupId [email protected] -AccessRight RestrictAccess -Description "Restrict this app to members of distribution group EvenUsers."

• AppId: your Azure App
• PolicyScopeGroupId: your Mail-enabled security group address

! Changes to application access policies can take longer than 1 hour to take effect in Microsoft Graph REST API calls

#3 Create new Credential for Azure App

Back to your Azure App and in Manage -> Certificates & secrets, upload certificate or add a client secret (copy value of client secret). You can create new certificate files by using this PowerShell script: Create-SelfSignedCertificate.ps1

#4 Set config in CSharp - Send email via MSGraph

The last step is setup AppSecret.config files:

<appSettings>
	<!-- Azure App MS Graph config: -->
	<add key = "tenantId" value = "00000000-0000-0000-0000-000000000000" />
	<add key = "clientId" value = "00000000-0000-0000-0000-000000000000" />
	<!-- byClientSecret: -->
	<add key = "clientSecret" value = "--qwertyuiopasdfghjklzxcvbnm0123456789--" />
	<!-- byCertificatePath: -->
	<add key = "ertificatePath" value = "*.pfx" />
	<add key = "certificatePass" value = "password" />
	<!-- byCertificateThumbprint: -->
	<add key = "certificateThumbp1rint" value = "QWERTYUIOPASDFGHJKLZXCVBNM0123456789QWER" />
</appSettings>

Setup this config depending on what type of authorization you have chosen for the application.

About me

If you like my work, consider visiting mine blog: Karol Kozłowski | CitDev