Mail traffic statistics

# Review required modules and connection steps before running.
# Connect to Microsoft Graph or Exchange Online as needed for this script.

param(
    [int] $LookbackDays = 92,
    [string] $StartDate = (Get-Date).AddDays(-$LookbackDays); $EndDate = (Get-Date).AddDays(+1),
    [string] $EndDate = (Get-Date)
)
 
CLS
# Check that we are connected to Exchange Online
$ModulesLoaded = Get-Module | Select Name
If (!($ModulesLoaded -match "ExchangeOnlineManagement")) {Write-Host "Please connect to the Exchange Online Management module and then restart the script"; break}
 
[array]$SenderData = Get-MailTrafficSummaryReport -Category TopMailSender -StartDate $StartDate -EndDate $EndDate | Select-Object C1, C2
[array]$RecipientData = Get-MailTrafficSummaryReport -Category TopMailRecipient -StartDate $StartDate -EndDate $EndDate | Select-Object C1, C2
$MbxReport = [System.Collections.Generic.List[Object]]::new()
 
$Mbx = Get-ExoMailbox -RecipientTypeDetails UserMailbox -ResultSize Unlimited
ForEach ($M in $Mbx) {
Write-Host "Processing" $M.DisplayName
# Check each email proxy address to see if it was used to send email
[int]$TotalSentMessages = 0 ; [int]$Messages = 0
ForEach ($A in $M.EmailAddresses) {
      If ($A.Substring(0,4) -eq "smtp") {
         $Messages = $SenderData | ? {$_.C1 -eq $A.Split(":")[1] } | Select -ExpandProperty C2
         # Write-Host "Messages found for" $A " " $Messages
         $TotalSentMessages = ($TotalSentMessages + $Messages) }
}
# Check each email proxy address to see if it was used to receive email
[int]$TotalReceivedMessages = 0 ; [int]$Messages = 0
ForEach ($A in $M.EmailAddresses) {
      If ($A.Substring(0,4) -eq "smtp") {
         $Messages = $RecipientData | ? {$_.C1 -eq $A.Split(":")[1] } | Select -ExpandProperty C2
         Write-Host "Messages found for" $A " " $Messages
         $TotalReceivedMessages = ($TotalReceivedMessages + $Messages) }
}
     $ReportLine = [PSCustomObject] @{
        User                = $M.DisplayName
        Address             = $M.UserPrincipalName
        "Sent messages"     = $TotalSentMessages
        "Received messages" = $TotalReceivedMessages }
      $MbxReport.Add($ReportLine)
}
$MbxReport | Out-GridView