ExportExchangeOnlineContacts.ps1

#Specify users you need to extract contactlist from.
$users = "alexander@contoso.com"

#Specify contactlist folder you need to export. Have added wildcard in the request, so if you are exporting all folders thats starts with Skype, enter "Skype" as foldername.
#Enter "root" as foldername if you want all contacts that are not in a folder.
$folder = "skype"


function Get-MSGraphAppToken{
    <#  .SYNOPSIS
        Get an app based authentication token required for interacting with Microsoft Graph API
    .PARAMETER TenantID
        A tenant ID should be provided.
 
    .PARAMETER ClientID
        Application ID for an Azure AD application. Uses by default the Microsoft Intune PowerShell application ID.
 
    .PARAMETER ClientSecret
        Web application client secret.
        
    .EXAMPLE
        # Manually specify username and password to acquire an authentication token:
        Get-MSGraphAppToken -TenantID $TenantID -ClientID $ClientID -ClientSecert = $ClientSecret 
    .NOTES
        Author: Jan Ketil Skanke
        Contact: @JankeSkanke
        Created: 2020-15-03
        Updated: 2020-15-03
 
        Version history:
        1.0.0 - (2020-03-15) Function created      
    #>
[CmdletBinding()]
    param (
        [parameter(Mandatory = $true, HelpMessage = "Your Azure AD Directory ID should be provided")]
        [ValidateNotNullOrEmpty()]
        [string]$TenantID,
        [parameter(Mandatory = $true, HelpMessage = "Application ID for an Azure AD application")]
        [ValidateNotNullOrEmpty()]
        [string]$ClientID,
        [parameter(Mandatory = $true, HelpMessage = "Azure AD Application Client Secret.")]
        [ValidateNotNullOrEmpty()]
        [string]$ClientSecret
        )
Process {
    $ErrorActionPreference = "Stop"
       
    # Construct URI
    $uri = "https://login.microsoftonline.com/$tenantId/oauth2/v2.0/token"
    # Construct Body
    $body = @{
        client_id     = $clientId
        scope         = "https://graph.microsoft.com/.default"
        client_secret = $clientSecret
        grant_type    = "client_credentials"
        }
    
    try {
        $MyTokenRequest = Invoke-WebRequest -Method Post -Uri $uri -ContentType "application/x-www-form-urlencoded" -Body $body -UseBasicParsing
        $MyToken =($MyTokenRequest.Content | ConvertFrom-Json).access_token
            If(!$MyToken){
                Write-Warning "Failed to get Graph API access token!"
                Exit 1
            }
        $MyHeader = @{"Authorization" = "Bearer $MyToken" }
       }
    catch [System.Exception] {
        Write-Warning "Failed to get Access Token, Error message: $($_.Exception.Message)"; break
    }
    return $MyHeader
    }
}
$tenantId = 'xxxxxxxx'
$ClientID = 'xxxxxxxx'
$ClientSecret = "xxxxxxxx"
$global:Header = Get-MSGraphAppToken -TenantID $tenantId -ClientID $ClientID -ClientSecret $ClientSecret 

function RefreshToken{
    Process{
        if(!$global:stopwatch){$global:stopwatch =  [system.diagnostics.stopwatch]::StartNew()}
        if(($global:stopwatch.Elapsed).Minutes -eq 45){
            $global:stopwatch =  [system.diagnostics.stopwatch]::StartNew()
            $global:Header = Get-MSGraphAppToken -TenantID $tenantId -ClientID $ClientID -ClientSecret $ClientSecret 
        }
    }
}
function Get-GraphRequest($uri){


Process {   
    $ErrorActionPreference = "Stop"

    try {
    #Graph API request that loops through every '@odata.nextLink'.
    $content = while (-not [string]::IsNullOrEmpty($Uri)) {

        # API Call
        Write-Host "`r`nQuerying $Uri..." -ForegroundColor Yellow
        try{
        RefreshToken
        $apiCall = Invoke-WebRequest -Method "GET" -Uri $Uri -ContentType "application/json" -Headers $global:Header -ErrorAction Stop -UseBasicParsing
        }
        catch{
            Start-Sleep -Seconds 30
            $apiCall = Invoke-WebRequest -Method "GET" -Uri $Uri -ContentType "application/json" -Headers $global:Header -ErrorAction Stop -UseBasicParsing
        }

        $nextLink = $null
        $Uri = $null

        if ($apiCall.Content) {
            

            # Check if any data is left
            $nextLink = $apiCall.Content | ConvertFrom-Json | Select-Object '@odata.nextLink'
            $Uri = $nextLink.'@odata.nextLink'

            $apiCall.Content | ConvertFrom-Json

        }

    }
    }
    catch [System.Exception] {
        Write-Warning "Failed to complete request, Error message: $($_.Exception.Message)"; break
    }


  

        return $content.value

}
}


foreach($user in $users){
if($folder -eq 'root'){
$usercontactfolders = Invoke-RestMethod -Method GET -Headers $global:Header "https://graph.microsoft.com/v1.0/users/$($user)/contactfolders/contacts"

foreach($usercontactfolder in $usercontactfolders){
$contacts = Get-GraphRequest -uri "https://graph.microsoft.com/v1.0/users/$($user)/contactfolders/$($usercontactfolder.id)/contacts"
$customcontacts = @()
foreach($contact in $contacts){
    
    $myObject = [PSCustomObject]@{
    Name = $contact.displayName
    email = ($contact.emailaddresses).name

}
$customcontacts += $myObject


}
$customcontacts | Export-Csv "c:\temp\$($user)-root.csv" -NoTypeInformation
}
}
Else{

$usercontactfolders = Get-GraphRequest -uri "https://graph.microsoft.com/v1.0/users/$($user)/contactfolders" | Where-Object{$_.displayname -like "$($folder)*"}

foreach($usercontactfolder in $usercontactfolders){
$contacts = Get-GraphRequest -uri "https://graph.microsoft.com/v1.0/users/$($user)/contactfolders/$($usercontactfolder.id)/contacts" 
$customcontacts = @()
foreach($contact in $contacts){
    
    $myObject = [PSCustomObject]@{
    Name = $contact.displayName
    email = ($contact.emailaddresses).name
}
$customcontacts += $myObject


}
$customcontacts | Export-Csv "c:\temp\$($user)-$($usercontactfolder.displayname).csv" -NoTypeInformation
}
}

}