<#
=============================================================================================
Name:           Export Dynamic Distribution Group Members Report
Version:        2.0
Website:        o365reports.com

Script Highlights:
~~~~~~~~~~~~~~~~~~

1.The script can be executed with MFA enabled account.
2.Allows you to filter the output based on group size (i.e., Members count).
3.You can choose to either “export members of all Dynamic Distribution Groups” or pass an input file to get members of specific groups alone. 
4.Output can be filtered to list Empty group. i.e., DDL without members
5.Exports the result to CSV 
6.You can get members count based on Member Type such as user mailbox, Group mailbox, shared mailbox, contact, etc
7.Above all, script stores output in nicely formatted 2 CSV files. One with detailed information and another with summary information.
8.Dynamic Distribution Group – Summary Report : Following are the columns available
   a.Group Display Name,
   b.Primary SMTP Address,  
   c.Group Alias,
   d.Group Manager,
   e.Hidden From Address List,
   f.Group Members Count,
   g.Members Count by Type
9.Dynamic Distribution Group – Detailed Members Report : Following are the columns available
   a.Group Display Name,
   b.Primary SMTP Address,  
   c.Group Alias,
   d.Group Manager,
   e.Group Members Count,
   f.Group Members,
   g.Member Email Address
   h.Member Type 

For detailed script execution:  https://o365reports.com/2019/03/23/export-dynamic-distribution-group-members-to-csv/
============================================================================================
#>

#Accept input parameter
Param
(
    [Parameter(Mandatory = $false)]
    [string]$GroupNamesFile,
    [switch]$IsEmpty,
    [int]$MinGroupMembersCount,
    [string]$UserName,
    [string]$Password,
    [Switch]$NoMFA
)

#Get group members
Function Get_Members
{
 $DisplayName=$_.DisplayName
 Write-Progress -Activity "`n     Processed Group count: $Count "`n"  Getting members of: $DisplayName"
 $Alias=$_.Alias
 $EmailAddress=$_.PrimarySmtpAddress
 $HiddenFromAddressList=$_.HiddenFromAddressListsEnabled
 $RecipientFilter=$_.RecipientFilter
 $RecipientHash=@{}
 for($KeyIndex = 0; $KeyIndex -lt $RecipientTypeArray.Length; $KeyIndex += 2)
 {
  $key=$RecipientTypeArray[$KeyIndex]
  $Value=$RecipientTypeArray[$KeyIndex+1]
  $RecipientHash.Add($key,$Value)
 }
 $Manager=$_.ManagedBy
 if($Manager -eq $null)
 { 
  $Manager="-"
 }
 $Recipient=""
 $Members=Get-Recipient -ResultSize unlimited -RecipientPreviewFilter $RecipientFilter
 #GroupSize Filter
 if(([int]$MinGroupMembersCount -ne "") -and ($Members.count -lt [int]$MinGroupMembersCount))
 {
  $Print=0
 }

 #Empty Group Filter
 elseif($Members.Count -eq 0)
 {
  $Member="No Members"
  $RecipientTypeDetail="-"
  Print_Output
 }

 #Loop through each member in a group
 else
 {
  foreach($Member in $Members)
  {
   if($IsEmpty.IsPresent)
   {
    $Print=0
    break
   }
   #Get Counts by RecipientTypeDetail
   $RecipientTypeDetail=$Member.RecipientTypeDetails
   $MemberEmail=$Member.PrimarySMTPAddress
   foreach($key in [object[]]$Recipienthash.Keys)
   {
    if(($RecipientTypeDetail -eq $key) -eq "true")
    {
     [int]$RecipientHash[$key]+=1
    }
   }
   Print_Output
  }
 }
 
 #Export Summary Report
 if($Print -eq 1)
 {
  #Order RecipientTypeDetail based on count
  $Hash=@{}
  $Hash=$RecipientHash.GetEnumerator() | Sort-Object -Property value -Descending |foreach{
   if([int]$($_.Value) -gt 0 )
   {
    if($Recipient -ne "")
    { $Recipient+=";"} 
    $Recipient+=@("$($_.Key) - $($_.Value)")    
   }
   if($Recipient -eq "")
   {$Recipient="-"}
  }
  $Output=@{'DisplayName'=$DisplayName;'PrimarySmtpAddress'=$EmailAddress;'Alias'=$Alias;'Manager'=$Manager;'GroupMembersCount'=$Members.Count;'HiddenFromAddressList'=$HiddenFromAddressList;'MembersCountByType'=$Recipient} 
  $Outputs= New-Object PSObject -Property $Output
  $Outputs | Select-Object DisplayName,PrimarySmtpAddress,Alias,Manager,HiddenFromAddressList,GroupMembersCount,MembersCountByType | Export-Csv -Path $ExportSummaryCSV -Notype -Append
 }
}

#Print Detailed Output
Function Print_Output
{
 if($Print=1)
 {
  $Result=@{'DisplayName'=$DisplayName;'PrimarySmtpAddress'=$EmailAddress;'Alias'=$Alias;'Manager'=$Manager;'GroupMembersCount'=$Members.Count; 'Members'=$Member; 'MemberEmail'= $MemberEmail; 'MemberType'=$RecipientTypeDetail} 
  $Results= New-Object PSObject -Property $Result 
  $Results | Select-Object DisplayName,PrimarySmtpAddress,Alias,Manager,GroupMembersCount,Members,MemberEmail,MemberType | Export-Csv -Path $ExportCSV -Notype -Append
 }
}

Function main()
{

 #Get a list of RecipientTypeDetail
 $RecipientTypeArray=Get-Content -Path .\RecipientTypeDetails.txt -ErrorAction Stop

 #Check for EXO v2 module inatallation
 $Module = Get-Module ExchangeOnlineManagement -ListAvailable
 if($Module.count -eq 0) 
 { 
  Write-Host Exchange Online PowerShell V2 module is not available  -ForegroundColor yellow  
  $Confirm= Read-Host Are you sure you want to install module? [Y] Yes [N] No 
  if($Confirm -match "[yY]") 
  { 
   Write-host "Installing Exchange Online PowerShell module"
   Install-Module ExchangeOnlineManagement -Repository PSGallery -AllowClobber -Force
   Import-Module ExchangeOnlineManagement
  } 
  else 
  { 
   Write-Host EXO V2 module is required to connect Exchange Online.Please install module using Install-Module ExchangeOnlineManagement cmdlet. 
   Exit
  }
 } 
 #Check for Azure AD module
 $Module = Get-Module MsOnline -ListAvailable
 if($Module.count -eq 0) 
 { 
  Write-Host MSOnline module is not available  -ForegroundColor yellow  
  $Confirm= Read-Host Are you sure you want to install the module? [Y] Yes [N] No 
  if($Confirm -match "[yY]") 
  { 
   Write-host "Installing MSOnline PowerShell module"
   Install-Module MSOnline -Repository PSGallery -AllowClobber -Force
   Import-Module MSOnline
  } 
  else 
  { 
   Write-Host MSOnline module is required to generate the report.Please install module using Install-Module MSOnline cmdlet. 
   Exit
  }
 }

 #Authentication using non-MFA
 if($NoMFA.IsPresent)
 {
  #Storing credential in script for scheduling purpose/ Passing credential as parameter
  if(($UserName -ne "") -and ($Password -ne ""))
  { 
   $SecuredPassword = ConvertTo-SecureString -AsPlainText $Password -Force
   $Credential  = New-Object System.Management.Automation.PSCredential $UserName,$SecuredPassword
  }
  else
  {
   $Credential=Get-Credential -Credential $null
  }
  Write-Host "Connecting Azure AD..."
  Connect-MsolService -Credential $Credential | Out-Null
  Write-Host "Connecting Exchange Online PowerShell..."
  Connect-ExchangeOnline -Credential $Credential
 }
 #Connect to Exchange Online and AzureAD module using MFA 
 else
 {
  Write-Host "Connecting Exchange Online PowerShell..."
  Connect-ExchangeOnline
  Write-Host "Connecting Azure AD..."
  Connect-MsolService | Out-Null
 }

 #Friendly DateTime conversion
 if($friendlyTime.IsPresent)
 {
  If(((Get-Module -Name PowerShellHumanizer -ListAvailable).Count) -eq 0)
  {
   Write-Host Installing PowerShellHumanizer for Friendly DateTime conversion
   Install-Module -Name PowerShellHumanizer
  }
 }

 #Set output file 
 $ExportCSV=".\DynamicDistributionGroup-DetailedMembersReport_$((Get-Date -format yyyy-MMM-dd-ddd` hh-mm` tt).ToString()).csv" #Detailed report
 $ExportSummaryCSV=".\DynamicDistributionGroup-SummaryReport_$((Get-Date -format yyyy-MMM-dd-ddd` hh-mm` tt).ToString()).csv" #Summary report

 
 $Result=""  
 $Results=@() 
 $Count=1

 #Check for input file
 if ($GroupNamesFile -ne "") 
 { 
  #We have an input file, read it into memory 
  $DDG=@()
  $DDG=Import-Csv -Header "DisplayName" $GroupNamesFile
  foreach($item in $DDG)
  {
   Get-DynamicDistributionGroup -Identity $item.displayname | Foreach{
   $Print=1
   Get_Members}
   $Count++
  }
 }
 else
 {
  #Get all dynamic distribution group
  Get-DynamicDistributionGroup | Foreach{
  $Print=1
  Get_Members
  $Count++}
 }

 #Open output file after execution 
 Write-Host `nScript executed successfully
 if((Test-Path -Path $ExportCSV) -eq "True")
 {
  Write-Host ""
  Write-Host " Detailed report available in:" -NoNewline -ForegroundColor Yellow 
  Write-Host $ExportCSV `n
  Write-host " Summary report available in:" -NoNewline -ForegroundColor Yellow 
  Write-Host $ExportSummaryCSV
  Write-Host `n~~ Script prepared by AdminDroid Community ~~`n -ForegroundColor Green
  Write-Host "~~ Check out " -NoNewline -ForegroundColor Green; Write-Host "admindroid.com" -ForegroundColor Yellow -NoNewline; Write-Host " to get access to 1800+ Microsoft 365 reports. ~~" -ForegroundColor Green `n`n
  $Prompt = New-Object -ComObject wscript.shell  
  $UserInput = $Prompt.popup("Do you want to open output file?",`  
  0,"Open Output File",4)  
  If ($UserInput -eq 6)  
  {  
   Invoke-Item "$ExportCSV"  
   Invoke-Item "$ExportSummaryCSV"
  } 
 }
 Else
 {
  Write-Host No DynamicDistributionGroup found
 }
 #Clean up session 
 Disconnect-ExchangeOnline -Confirm:$false -InformationAction Ignore -ErrorAction SilentlyContinue
}
. main