Connect EXO EWS With User Cred OAUTH

Connect EWS With User Cred OAUTH.ps1

#You need AzureAD Module (Save-Module AzureAD -Path C:\temp)
#You need EWS API 2.2 (www.microsoft.com/en-us/download/details.aspx?id=35371)


$UserPrincipalName = "user@TENANTNAME.onmicrosoft.com"
$resourceUri = "https://outlook.office365.com"
$AzureADDLLPath = "C:\Temp\AzureAD"

#EWSEditor ClientId used since it was already registered with the right permission
$clientid = "0e4bf2e2-aa7d-46e8-aa12-263adeb3a62b"
$redirectUri = "https://microsoft.com/EwsEditor"
$AuthAuthority = "https://login.windows.net/common"

# Load ADAL Assemblies
$adal = $AzureADDLLPath + "\Microsoft.IdentityModel.Clients.ActiveDirectory.dll"
[System.Reflection.Assembly]::LoadFrom($adal) | Out-Null

$authContext = New-Object "Microsoft.IdentityModel.Clients.ActiveDirectory.AuthenticationContext" -ArgumentList $AuthAuthority
$PromptBehavior = [Microsoft.IdentityModel.Clients.ActiveDirectory.PromptBehavior]::Auto
$platformParam = New-Object "Microsoft.IdentityModel.Clients.ActiveDirectory.PlatformParameters" -ArgumentList $PromptBehavior
$userId = New-Object "Microsoft.IdentityModel.Clients.ActiveDirectory.UserIdentifier" -ArgumentList $UserPrincipalName, "OptionalDisplayableId"
$authResult = $authContext.AcquireTokenAsync($resourceUri, $clientId, $redirectUri, $platformParam, $userId)

#Load EWS DLL
Add-Type -Path "C:\Program Files\Microsoft\Exchange\Web Services\2.2\Microsoft.Exchange.WebServices.dll" -ErrorAction Stop	

#Build EWS Service and Credential
$Service = new-object Microsoft.Exchange.WebServices.Data.ExchangeService([Microsoft.Exchange.WebServices.Data.ExchangeVersion]::Exchange2013_SP1);
$service.Credentials  = new-object  Microsoft.Exchange.WebServices.Data.OAuthCredentials($authResult.result.CreateAuthorizationHeader())

#Build EWS URL
$URL = "$($resourceUri)/ews/exchange.asmx"
$service.Url = [system.URI] $URL

#Send EWS request to get the last 100 emails
$inbox = [Microsoft.Exchange.WebServices.Data.Folder]::Bind($service,[Microsoft.Exchange.WebServices.Data.WellKnownFolderName]::Inbox)
[array]$Allmails = $inbox.FindItems(100)
$Allmails | select Subject