List of All Emails in Archive Folder

lpmdvip Try again please, I've added more error controls and fixed a couple of variables names that I miss in the last pass. Editing in my phone can be har as I don't have an editor with coloring help xD.

<#
.SYNOPSIS
    Get MBXs Stats, User Attribute(s), Gets Subject Emails in Archive Folder (Only if the user has a department assigned)
.DESCRIPTION
 Requires you to be a member of groups: eDiscoveryManager and Compliance Administrator to be able to use the Compliance cmdlets properly. 
.NOTES
    Author:     Erick A. Moreno
    Email:      emoreno@request-script.com
    Date:       17 Jan 2020
    PowerShell: v3
.References
#requested: https://techcommunity.microsoft.com/t5/windows-powershell/list-of-all-emails-in-archive-folder/m-p/1178048#M1045
#>

$CredentialsFolder = "$home\Documents\"
$WorkingDir        = "$home\Documents"
$ScriptTime        = Get-Date -UFormat "%m%d%Y-%H%M"

#region Functions
Function _Get-Sessions
 {
  Param(
        [Parameter(Mandatory=$true)]$CredentialsFolder,
        [Parameter(Mandatory=$true)]$CredentialsFileName,
        [Parameter(Mandatory=$false)]$InlcudeSecSession,
        [Parameter(Mandatory=$false)]$InlcudeExoSession
       )
  
  #region Check for Credentials File
  $TargetCredPath = $CredentialsFolder #Credential XML File Location
  $TargetCredName = $TargetCredPath + $CredentialsFileName
  #Write-Host $TargetCredName
  If(Test-Path $TargetCredName)
   {
    $TargetCred = Import-Clixml $TargetCredName
   }
  Else
   {
    $Cred = Get-Credential 
    $Cred | Export-CliXml -Path $(Join-Path -path $TargetCredPath -ChildPath RemotePS.HCH.cred)
    $TargetCred = Import-Clixml $TargetCredName
   }
  #endregion
  #region connections
  If($InlcudeExoSession -eq $true)
   {
    $Session  = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $TargetCred -Authentication Basic -AllowRedirection 
    $NoOutput = Import-PSSession $Session -AllowClobber -Prefix O365 -CommandName "*Mailbox*","*User*"
   }
  If($InlcudeSecSession -eq $true)
   {
    $Session2  = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.compliance.protection.outlook.com/powershell-liveid/ -Credential $TargetCred -Authentication Basic –AllowRedirection
    $NoOutput2 = Import-PSSession $Session2 -Prefix 365Sec -CommandName "*Compliance*" -AllowClobber
   }
  #endregion
  Return  $Session,$Session2
 }
#endregion
#region Open PS Sessions
Get-PSSession | Remove-PSSession
$TenantSession = _Get-Sessions -CredentialsFolder $CredentialsFolder -CredentialsFileName RemotePS.HCH.cred -InlcudeSecSession $true -InlcudeExoSession $true
#endregion

$MBXs = Get-O365Mailbox -ResultSize Unlimited

$Counter      = @($MBXs).count
$Results      = @()
$NoDepartment = @()
$ErrorsLog       = @()
$Counter

Foreach($MBX in $MBXs)
 {
  #Start-Sleep -Milliseconds 300
  $PsExOSessionState = $(Get-PsSession $TenantSession[0].Id).State  
  $PsSecSessionState = $(Get-PsSession $TenantSession[1].Id).State 
   
  If($($Counter/100) -match '^[0-9]+$' -or $PsExOSessionState -ne "Opened" -or $PsSecSessionState -ne "Opened")
   {
    Remove-PSSession $TenantSession[0].Id -Confirm:$false
    Remove-PSSession $TenantSession[1].Id -Confirm:$false
    Write-Host "Opening a new Session Each 100 iterations" -ForegroundColor Yellow
    $TenantSession = _Get-Sessions -CredentialsFolder $CredentialsFolder -CredentialsFileName RemotePS.HCH.cred -InlcudeSecSession $true -InlcudeExoSession $true
   }

  Write-Host "($Counter) Working On MBX: $($MBX.PrimarySmtpAddress)" -ForegroundColor Cyan
  $Stats       = $null
  $UserData    = $null
  $FolderItems = $null
  $UserData    = Get-O365User $MBX.PrimarySmtpAddress
  $LastLogon   = $null

  If(![string]::IsNullOrEmpty($($UserData.Department)))
     {
      Try
       { 
        $FolderID   = $null
        $FolderInfo = Get-O365MailboxFolderStatistics -Identity $MBX.PrimarySmtpAddress -ErrorAction Stop | Where {$_.Name -eq “Archive”} | Select Name,ItemsInFolder,FolderID #Add Folders as needed
        $FolderID   = $FolderInfo.FolderId
        If(![string]::IsNullOrEmpty($FolderID))
         {
          #region decoding From: https://docs.microsoft.com/en-us/microsoft-365/compliance/use-content-search-for-targeted-collections#step-1-run-the-script-to-get-a-list-of-folders-for-a-mailbox-or-site
          $encoding                = [System.Text.Encoding]::GetEncoding("us-ascii")
          $nibbler                 = $encoding.GetBytes("0123456789ABCDEF");
          $folderIdBytes           = [Convert]::FromBase64String($FolderID)
          $indexIdBytes            = New-Object byte[] 48
          $indexIdIdx              = 0
          $folderIdBytes           | select -skip 23 -First 24 | %{$indexIdBytes[$indexIdIdx++]=$nibbler[$_ -shr 4];$indexIdBytes[$indexIdIdx++]=$nibbler[$_ -band 0xF]}
          $folderQueryeDiscovery   = "folderid:$($encoding.GetString($indexIdBytes))"
          #endregion
          
          $Split = $null
          $Split = $MBX.PrimarySmtpAddress -split "@" 
          $SearchName = "($Counter) Search Archive ($($Split[0]))"
          
          $Search = New-365SecComplianceSearch -Name  $SearchName -ContentMatchQuery $folderQueryeDiscovery -ExchangeLocation All -ErrorAction Stop
          Start-365SecComplianceSearch -Identity  $SearchName -ErrorAction Stop
          
          Do
           {
            $SearchStatus = Get-365SecComplianceSearch $Search.Name -ErrorAction Stop
            Write-Progress -Status $($SearchStatus.Status) -Activity "Search For MBX: $($MBX.DisplayName)" -PercentComplete $($SearchStatus.JobProgress)
           }While($SearchStatus.Status -ne "Completed")
          
          $Action = New-365SecComplianceSearchAction -SearchName  $SearchName -Preview -ErrorAction Stop
          
          $PsExOSessionState = $(Get-PsSession $TenantSession[0].Id).State  
          $PsSecSessionState = $(Get-PsSession $TenantSession[1].Id).State  
          
          If($PsSecSessionState -ne "Opened")
           {
            Remove-PSSession $TenantSession[0].Id -Confirm:$false
            Remove-PSSession $TenantSession[1].Id -Confirm:$false
            Write-Host "Opening a new Session" -ForegroundColor Yellow
            $TenantSession = _Get-Sessions -CredentialsFolder $CredentialsFolder -CredentialsFileName RemotePS.HCH.cred -InlcudeSecSession $true -InlcudeExoSession $true
           }    
          
           Do
            {
             $ActionStatus = Get-365SecComplianceSearchAction -Identity $Action.Name -ErrorAction Stop
             Write-Progress -Status $($ActionStatus.Status) -Activity "Search Action Review For MBX: $($MBX.DisplayName)" -PercentComplete $($ActionStatus.JobProgress)
            }While($ActionStatus.Status -ne "Completed")
          
          $PsExOSessionState = $(Get-PsSession $TenantSession[0].Id).State  
          $PsSecSessionState = $(Get-PsSession $TenantSession[1].Id).State  
          
          If($PsSecSessionState -ne "Opened")
           {
            Remove-PSSession $TenantSession[0].Id -Confirm:$false
            Remove-PSSession $TenantSession[1].Id -Confirm:$false
            Write-Host "Opening a new Session" -ForegroundColor Yellow
            $TenantSession = _Get-Sessions -CredentialsFolder $CredentialsFolder -CredentialsFileName RemotePS.HCH.cred -InlcudeSecSession $true -InlcudeExoSession $true
           }
          
          $Subjects = $($ActionStatus.Results -split ';' | where{$_ -like "*subject*"}).replace("Subject:",'') -join ';'
          
          Remove-365SecComplianceSearch -Identity $SearchName -Confirm:$false -ErrorAction Stop
          
          If(![string]::IsNullOrEmpty($Stats.LastLogonTime))
           {
            $LastLogon = $Stats.LastLogonTime.ToString()
           }
          $Properties  = [Ordered]@{
                                    DisplayName                  = $MBX.DisplayName
                                    EmailSubjectsInArchiveFolder = $Subjects 
                                    Department                   = $UserData.Department 
                                    ArchiveItems                 = $($FolderItems | where{$_.Name -eq "Archive"}).ItemsInFolder
                                    LastLogon                    = $LastLogon
                                    lastuseractiontime           = $Stats.lastuseractiontime 
                                    UserPrincipalName            = $MBX.UserPrincipalName
                                    FolderIdQuery                = $folderQueryeDiscovery
                                   }
          
          $Results += New-Object PSObject -Property $Properties
         }#Folder ID Exist?
        Else
         {
          Write-Host "Archive Folder Does not Exists for MBX: $($MBX.PrimarySmtpAddress)" -ForegroundColor Yellow
          Throw "Archive Folder Does not Exists for MBX: $($MBX.PrimarySmtpAddress)"
         }
       }
     Catch
      {
       Write-Host "Error Found During MBX Search: $($MBX.PrimarySmtpAddress): $($Error[0])" -ForegroundColor Red
       $Properties3  = [Ordered]@{
                                  PrimarySmtpAddress = $MBX.PrimarySmtpAddress
                                  Error              = $Error[0]
                                 }
       $ErrorsLog += New-Object PSObject -Property $Properties3
      }
   }
  Else
   {
    Write-Host "Department Field is Empty Skipping MBX: $($MBX.PrimarySmtpAddress)"
    $Properties2  = [Ordered]@{
                               PrimarySmtpAddress = $MBX.PrimarySmtpAddress
                              }
    $NoDepartment += New-Object PSObject -Property $Properties2
   }
  $Counter--
 }
 Remove-PSSession $TenantSession[0].Id -Confirm:$false
 Remove-PSSession $TenantSession[1].Id -Confirm:$false
 
 $Results      | Export-Csv -Path "$WorkingDir\ReportMBXsStats_$ScriptTime.csv"   -NoTypeInformation -Encoding UTF8 -Force
 $NoDepartment | Export-Csv -Path "$WorkingDir\NoDepartmentField_$ScriptTime.csv" -NoTypeInformation -Encoding UTF8 -Force
 $ErrorsLog    | Export-Csv -Path "$WorkingDir\Errors_$ScriptTime.csv"            -NoTypeInformation -Encoding UTF8 -Force
 
 Write-Host "Report Saved To: $WorkingDir\ReportMBXsStats_$ScriptTime.csv"                -ForegroundColor Cyan
 Write-Host "No Department Field Saved To: $WorkingDir\NoDepartmentField_$ScriptTime.csv" -ForegroundColor Cyan
 Write-Host "Errors  Saved To: $WorkingDir\Errors_$ScriptTime.csv"                        -ForegroundColor Cyan