Extracting Unused Mailbox Information from Mailbox Diagnostics
Recently, I posted a Petri.com article to report the availability of some new properties in the Export-MailboxDiagnosticLogs cmdlet. The properties record different kinds of mailbox activity, and I included a script to generate a report based on the properties. The output is a CSV file that can be opened in Excel or imported in Power BI. All is well.
I then had the idea that maybe it would be good to filter the output to find unused mailboxes and post that information to a Teams channel as a form of proactive notification to administrators. Not having endless time, I browsed the web to find a PowerShell script to serve as a starting point and found one that reports inactive Active Directory accounts. That’s not a long way from what I wanted to do, so I grabbed the code and edited it to fit my purpose.
Using Incoming Webhook Connector to Post to Teams
Posting messages to a Teams channel is easily done using the incoming webhook connector, one of the standard connectors available to all Microsoft 365 tenants to bring information sourced from applications into Teams and Microsoft 365 Groups. When you configure the connector for a channel, you get a webhook (unique identifier) to post messages to the channel.
I then filtered the set of mailboxes I created in the table generated by the previous script (see link above) to find mailboxes with no email activity over the last 90 days. If a mailbox has no activity in three months, it’s a good indicator that it is an unused mailbox. I then generate the necessary JSON format payload consumed by Teams and post the resulting message reporting the unused mailboxes to the webhook. Here’s the script:
# Script uses some code from https://www.thelazyadministrator.com/2018/12/11/post-inactive-users-as-a-microsoft-teams-message-with-powershell/
$WebHook = "https://outlook.office.com/webhook/42f6d6b0-c191-496d-85b4-bfd6e63e230b@b662313f-14fc-43a2-9a7a-d2e27f4f3478/IncomingWebhook/62c92a65258a416b90e969980ae4ebb1/eff4cd58-1bb8-4899-94de-795f656b4a18"
$InactiveTable = New-Object 'System.Collections.Generic.List[System.Object]'
$PersonImage = "https://img.icons8.com/cotton/2x/gender-neutral-user--v1.png"
$Today = (Get-Date)
ForEach ($R in $Report) {
$DaysSinceLastEmail = ((New-TimeSpan –Start $R.LastEmail –End $Today).Days)
If ($DaysSinceLastEmail -gt 90) {
$UserData = @{
ActivityTitle = "$($R.Mailbox)"
ActivitySubTitle = "-----------------------------------------------"
ActivityText = "$($R.Mailbox)'s last email activity was on $($R.LastEmail)"
ActivityImage = $PersonImage
Facts = @(
@{
name = 'Mailbox:'
value = $R.Mailbox },
@{
name = 'Last Email activity:'
value = $R.LastEmail },
@{
name = 'Days since last activity:'
value = $DaysSinceLastEmail },
@{
name = 'Last active time (unreliable):'
value = $R.LastActive } )
}
$InactiveTable.Add($UserData)
Write-Host $R.Mailbox $R.LastEmail $DaysSince }}
$Body = ConvertTo-Json -Depth 8 @{
Title = "Possibly Inactive Office 365 Users"
Text = "There are $($InactiveTable.Count) users with no detected email activity for 90 days or more"
Sections = $InactiveTable }
# Only post if we have less than 25 items
If ($InactiveTable.Count -lt 25) {
Write-Host "Posting inactive account information to Teams" -ForegroundColor Yellow
Invoke-RestMethod -uri $WebHook -Method Post -body $body -ContentType 'application/json' }
Else {
Write-Host "Too many (" $InactiveTable.Count ") inactive accounts found to post to Teams... Spread the bad news another way" }
The message posted to Teams looks like the example shown in Figure 1:
Figure 1: Inactive Office 365 user information posted to a Teams channel
Remember the Teams Maximum Message Size
There’s nothing earth shattering in the code and plenty of similar examples are available online (such is the joy of PowerShell). What is important to note when you post to Teams is that the message is limited to a maximum size of 25 KB. If your message exceeds the limit, Teams responds with a HTTP 413 error similar to:
Microsoft Teams endpoint returned HTTP error 413 with ContextId tcid=982653230009892365,server=DB3PEPF00000461,cv=4LrmcZGylkmtD0uEToTT2g.0.
In my case, it seemed like the error happened if more than 28 or so items were in the list of reported accounts. This will obviously vary depending on how much data you try to post for each item.
For more information about using Teams and Microsoft 365 Groups with connectors, read the Office 365 for IT Pros eBook.
One issue I noted with this and I am not sure why is the script returns 15 inactive users and I send them all to teams however Teams only shows the first 10. I have removed information and the image etc to see if its a size issue, but it still only shows 10. Any ideas?
$InactiveTable = New-Object ‘System.Collections.Generic.List[System.Object]’
$PersonImage = “https://img.icons8.com/cotton/2x/gender-neutral-user–v1.png”
$Today = (Get-Date)
ForEach ($R in $Report) {
$DaysSinceLastEmail = ((New-TimeSpan –Start $R.LastEmail –End $Today).Days)
If ($DaysSinceLastEmail -gt 90) {
$UserData = @{
ActivityTitle = “$($R.Mailbox)”
ActivitySubTitle = “———————————————–”
ActivityText = “$($R.Mailbox)’s last email activity was on $($R.LastEmail)”
ActivityImage = $PersonImage
Facts = @(
@{
name = ‘Mailbox:’
value = $R.Mailbox },
@{
name = ‘Last Email activity:’
value = $R.LastEmail },
@{
name = ‘Days since last activity:’
value = $DaysSinceLastEmail },
@{
name = ‘Last active time (unreliable):’
value = $R.LastActive } )
}
$InactiveTable.Add($UserData)
Write-Host $R.Mailbox $R.LastEmail $DaysSince }}
$Body = ConvertTo-Json -Depth 8 @{
Title = “Possibly Inactive Office 365 Users”
Text = “There are $($InactiveTable.Count) users with no detected email activity for 90 days or more”
Sections = $InactiveTable }
# Only post if we have less than 25 items
If ($InactiveTable.Count -lt 25) {
Write-Host “Posting inactive account information to Teams” -ForegroundColor Yellow
Invoke-RestMethod -uri $WebHook -Method Post -body $body -ContentType ‘application/json’ }
Else {
Write-Host “Too many (” $InactiveTable.Count “) inactive accounts found to post to Teams… Spread the bad news another way” }
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Looks OK to me, but I have not run the code. I can’t – it has to run in your environment.
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Please try again.","form_title":"Office 365 for IT Pros","form_subtitle":null,"currency_search_text":"Country or Currency here","other_payment_option":"Other payment option","manage_payments_button_text":"Manage your payments","thank_you_message":"Thank you for supporting the work of Office 365 for IT Pros!","payment_confirmation_title":"Office 365 for IT Pros","receipt_title":"Your Receipt","print_receipt":"Print Receipt","email_receipt":"Email Receipt","email_receipt_sending":"Sending receipt...","email_receipt_success":"Email receipt successfully sent","email_receipt_failed":"Email receipt failed to send. Please try again.","receipt_payee":"Paid to","receipt_statement_descriptor":"This will show up on your statement as","receipt_date":"Date","receipt_transaction_id":"Transaction ID","receipt_transaction_amount":"Amount","refund_payer":"Refund from","login":"Log in to manage your payments","manage_payments":"Manage Payments","transactions_title":"Your Transactions","transaction_title":"Transaction Receipt","transaction_period":"Plan Period","arrangements_title":"Your Plans","arrangement_title":"Manage Plan","arrangement_details":"Plan Details","arrangement_id_title":"Plan ID","arrangement_payment_method_title":"Payment Method","arrangement_amount_title":"Plan Amount","arrangement_renewal_title":"Next renewal date","arrangement_action_cancel":"Cancel Plan","arrangement_action_cant_cancel":"Cancelling is currently not available.","arrangement_action_cancel_double":"Are you sure you'd like to cancel?","arrangement_cancelling":"Cancelling Plan...","arrangement_cancelled":"Plan Cancelled","arrangement_failed_to_cancel":"Failed to cancel plan","back_to_plans":"\u2190 Back to Plans","update_payment_method_verb":"Update","sca_auth_description":"Your have a pending renewal payment which requires authorization.","sca_auth_verb":"Authorize renewal payment","sca_authing_verb":"Authorizing payment","sca_authed_verb":"Payment successfully authorized!","sca_auth_failed":"Unable to authorize! Please try again.","login_button_text":"Log in","login_form_has_an_error":"Please check and fix the errors above","uppercase_search":"Search","lowercase_search":"search","uppercase_page":"Page","lowercase_page":"page","uppercase_items":"Items","lowercase_items":"items","uppercase_per":"Per","lowercase_per":"per","uppercase_of":"Of","lowercase_of":"of","back":"Back to plans","zip_code_placeholder":"Zip\/Postal Code","download_file_button_text":"Download File","input_field_instructions":{"tip_amount":{"placeholder_text":"How much would you like to tip?","initial":{"instruction_type":"normal","instruction_message":"How much would you like to tip? Choose any currency."},"empty":{"instruction_type":"error","instruction_message":"How much would you like to tip? Choose any currency."},"invalid_curency":{"instruction_type":"error","instruction_message":"Please choose a valid currency."}},"recurring":{"placeholder_text":"Recurring","initial":{"instruction_type":"normal","instruction_message":"How often would you like to give this?"},"success":{"instruction_type":"success","instruction_message":"How often would you like to give this?"},"empty":{"instruction_type":"error","instruction_message":"How often would you like to give this?"}},"name":{"placeholder_text":"Name on Credit Card","initial":{"instruction_type":"normal","instruction_message":"Enter the name on your card."},"success":{"instruction_type":"success","instruction_message":"Enter the name on your card."},"empty":{"instruction_type":"error","instruction_message":"Please enter the name on your card."}},"privacy_policy":{"terms_title":"Terms and conditions","terms_body":null,"terms_show_text":"View Terms","terms_hide_text":"Hide Terms","initial":{"instruction_type":"normal","instruction_message":"I agree to the terms."},"unchecked":{"instruction_type":"error","instruction_message":"Please agree to the terms."},"checked":{"instruction_type":"success","instruction_message":"I agree to the terms."}},"email":{"placeholder_text":"Your email address","initial":{"instruction_type":"normal","instruction_message":"Enter your email address"},"success":{"instruction_type":"success","instruction_message":"Enter your email address"},"blank":{"instruction_type":"error","instruction_message":"Enter your email address"},"not_an_email_address":{"instruction_type":"error","instruction_message":"Make sure you have entered a valid email address"}},"note_with_tip":{"placeholder_text":"Your note here...","initial":{"instruction_type":"normal","instruction_message":"Attach a note to your tip (optional)"},"empty":{"instruction_type":"normal","instruction_message":"Attach a note to your tip (optional)"},"not_empty_initial":{"instruction_type":"normal","instruction_message":"Attach a note to your tip (optional)"},"saving":{"instruction_type":"normal","instruction_message":"Saving note..."},"success":{"instruction_type":"success","instruction_message":"Note successfully saved!"},"error":{"instruction_type":"error","instruction_message":"Unable to save note note at this time. Please try again."}},"email_for_login_code":{"placeholder_text":"Your email address","initial":{"instruction_type":"normal","instruction_message":"Enter your email to log in."},"success":{"instruction_type":"success","instruction_message":"Enter your email to log in."},"blank":{"instruction_type":"error","instruction_message":"Enter your email to log in."},"empty":{"instruction_type":"error","instruction_message":"Enter your email to log in."}},"login_code":{"initial":{"instruction_type":"normal","instruction_message":"Check your email and enter the login code."},"success":{"instruction_type":"success","instruction_message":"Check your email and enter the login code."},"blank":{"instruction_type":"error","instruction_message":"Check your email and enter the login code."},"empty":{"instruction_type":"error","instruction_message":"Check your email and enter the login code."}},"stripe_all_in_one":{"initial":{"instruction_type":"normal","instruction_message":"Enter your credit card details here."},"empty":{"instruction_type":"error","instruction_message":"Enter your credit card details here."},"success":{"instruction_type":"normal","instruction_message":"Enter your credit card details here."},"invalid_number":{"instruction_type":"error","instruction_message":"The card number is not a valid credit card number."},"invalid_expiry_month":{"instruction_type":"error","instruction_message":"The card's expiration month is invalid."},"invalid_expiry_year":{"instruction_type":"error","instruction_message":"The card's expiration year is invalid."},"invalid_cvc":{"instruction_type":"error","instruction_message":"The card's security code is invalid."},"incorrect_number":{"instruction_type":"error","instruction_message":"The card number is incorrect."},"incomplete_number":{"instruction_type":"error","instruction_message":"The card number is incomplete."},"incomplete_cvc":{"instruction_type":"error","instruction_message":"The card's security code is incomplete."},"incomplete_expiry":{"instruction_type":"error","instruction_message":"The card's expiration date is incomplete."},"incomplete_zip":{"instruction_type":"error","instruction_message":"The card's zip code is incomplete."},"expired_card":{"instruction_type":"error","instruction_message":"The card has expired."},"incorrect_cvc":{"instruction_type":"error","instruction_message":"The card's security code is incorrect."},"incorrect_zip":{"instruction_type":"error","instruction_message":"The card's zip code failed validation."},"invalid_expiry_year_past":{"instruction_type":"error","instruction_message":"The card's expiration year is in the past"},"card_declined":{"instruction_type":"error","instruction_message":"The card was declined."},"missing":{"instruction_type":"error","instruction_message":"There is no card on a customer that is being charged."},"processing_error":{"instruction_type":"error","instruction_message":"An error occurred while processing the card."},"invalid_request_error":{"instruction_type":"error","instruction_message":"Unable to process this payment, please try again or use alternative method."},"invalid_sofort_country":{"instruction_type":"error","instruction_message":"The billing country is not accepted by SOFORT. Please try another country."}}}},"fetched_oembed_html":false}
One issue I noted with this and I am not sure why is the script returns 15 inactive users and I send them all to teams however Teams only shows the first 10. I have removed information and the image etc to see if its a size issue, but it still only shows 10. Any ideas?
As explained in the post, a post to Teams can be a maximum of 25KB. You’re probably hitting that limit…
Is this possible to run as Azure runbook only ?
I don’t know because I haven’t tried. Have a go and let us know how you get on.
Can you confirm I’ve merged these correctly. Have kind of been playing with this concept for the last day.
# Pull credential from Automation assets
$credObject = Get-AutomationPSCredential -Name “Redacted”
#Connect to Exchange Online
$ExchangeOnlineSession = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/PowerShell-LiveID -Credential $credObject -Authentication Basic -AllowRedirection
Import-Module (Import-PSSession -Session $ExchangeOnlineSession -AllowClobber -DisableNameChecking) -Global
# Teams Channel Hook#
$WebHook = “Redacted”
# Generate Mailbox Activity Report #
$Mbx = (Get-Recipient -RecipientTypeDetails UserMailbox -ResultSize Unlimited | Select DisplayName, DistinguishedName)
$Report = @()
ForEach ($M in $Mbx) {
Write-Host “Processing” $M.DisplayName
$Log = Export-MailboxDiagnosticLogs -Identity $M.DistinguishedName -ExtendedProperties
$xml = [xml]($Log.MailboxLog)
$LastEmail = ($xml.Properties.MailboxTable.Property | ? {$_.Name -like “LastEmailTimeCurrentValue”}).Value
$LastCalendar = ($xml.Properties.MailboxTable.Property | ? {$_.Name -like “LastCalendarTimeCurrentValue”}).Value
$LastContacts = ($xml.Properties.MailboxTable.Property | ? {$_.Name -like “LastContactsTimeCurrentValue”}).Value
$LastFile = ($xml.Properties.MailboxTable.Property | ? {$_.Name -like “LastFileTimeCurrentValue”}).Value
$Stats = (Get-MailboxStatistics -Identity $M.DistinguishedName)
$MbxSize = ($Stats.TotalItemSize.Value.ToString()).Split(“(“)[0]
$ReportLine = [PSCustomObject][Ordered]@{
Mailbox = $M.DisplayName
Items = $Stats.ItemCount
Size = $MbxSize
LastLogon = Get-Date($Stats.LastLogonTime) -Format g
LastActive = Get-Date($Stats.LastInteractionTime) -Format g
LastEmail = Get-Date($LastEmail) -Format g
LastCalendar = Get-Date($LastCalendar) -Format g
LastContacts = Get-Date($LastContacts) -Format g
LastFile = Get-Date($LastFile) -Format g}
$Report += $ReportLine }
Write-Host “Inactive Mailboxes $($($InactiveTable.count)”
# Teams Information Table #
$InactiveTable = New-Object ‘System.Collections.Generic.List[System.Object]’
$PersonImage = “https://img.icons8.com/cotton/2x/gender-neutral-user–v1.png”
$Today = (Get-Date)
ForEach ($R in $Report) {
$DaysSinceLastEmail = ((New-TimeSpan –Start $R.LastEmail –End $Today).Days)
If ($DaysSinceLastEmail -gt 90) {
$UserData = @{
ActivityTitle = “$($R.Mailbox)”
ActivitySubTitle = “———————————————–”
ActivityText = “$($R.Mailbox)’s last email activity was on $($R.LastEmail)”
ActivityImage = $PersonImage
Facts = @(
@{
name = ‘Mailbox:’
value = $R.Mailbox },
@{
name = ‘Last Email activity:’
value = $R.LastEmail },
@{
name = ‘Days since last activity:’
value = $DaysSinceLastEmail },
@{
name = ‘Last active time (unreliable):’
value = $R.LastActive } )
}
$InactiveTable.Add($UserData)
Write-Host $R.Mailbox $R.LastEmail $DaysSince }}
$Body = ConvertTo-Json -Depth 8 @{
Title = “Possibly Inactive Office 365 Users”
Text = “There are $($InactiveTable.Count) users with no detected email activity for 90 days or more”
Sections = $InactiveTable }
# Only post if we have less than 25 items
If ($InactiveTable.Count -lt 25) {
Write-Host “Posting inactive account information to Teams” -ForegroundColor Yellow
Invoke-RestMethod -uri $WebHook -Method Post -body $body -ContentType ‘application/json’ }
Else {
Write-Host “Too many (” $InactiveTable.Count “) inactive accounts found to post to Teams… Spread the bad news another way” }
Looks OK to me, but I have not run the code. I can’t – it has to run in your environment.