This script is one we’ve used in the past as a sales tool – Some companies tend to use their mailbox as a storage location more than just a mailbox. They save large attachments, use it as a personal CRM system or even just really like sending eachother large PDFs 😉
When mailboxes get too large your users will start experiencing performance or caching issues. It’s also just not a good practice to have huge mailboxes, just imagine you’ll want to work on a Remote Desktop or Windows Virtual Desktop server with a 60GB mailbox cached…
Anyway; to make sure that when users experience large growth in mailboxes I’ve been using the following monitoring set in our N-central RMM system. This monitoring script alerts whenever a user has a mailbox larger than 60GB. As always I’ve included two scripts: one for a single tenant, one for multiple tenants. As always, my scripts are using the Secure Application Model.
Multiple tenant script
$ApplicationId = 'xxxx-xxxx-xxx-xxxx-xxxx'
$ApplicationSecret = 'TheSecretTheSecret' | Convertto-SecureString -AsPlainText -Force
$TenantID = 'YourTenantID'
$RefreshToken = 'RefreshToken'
$ExchangeRefreshToken = 'ExchangeRefreshToken'
$upn = 'UPN-Used-To-Generate-Tokens'
$SizeToMonitor = 60
$credential = New-Object System.Management.Automation.PSCredential($ApplicationId, $ApplicationSecret)
$aadGraphToken = New-PartnerAccessToken -ApplicationId $ApplicationId -Credential $credential -RefreshToken $refreshToken -Scopes 'https://graph.windows.net/.default' -ServicePrincipal -Tenant $tenantID
$graphToken = New-PartnerAccessToken -ApplicationId $ApplicationId -Credential $credential -RefreshToken $refreshToken -Scopes 'https://graph.microsoft.com/.default' -ServicePrincipal -Tenant $tenantID
Connect-MsolService -AdGraphAccessToken $aadGraphToken.AccessToken -MsGraphAccessToken $graphToken.AccessToken
$customers = Get-MsolPartnerContract -All
$LargeMailboxes = @()
foreach ($customer in $customers) {
write-host "Getting started for $($Customer.name)" -foregroundcolor green
$token = New-PartnerAccessToken -ApplicationId 'a0c73c16-a7e3-4564-9a95-2bdf47383716'-RefreshToken $ExchangeRefreshToken -Scopes 'https://outlook.office365.com/.default' -Tenant $customer.TenantId
$tokenValue = ConvertTo-SecureString "Bearer $($token.AccessToken)" -AsPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential($upn, $tokenValue)
$customerId = $customer.DefaultDomainName
$session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri "https://ps.outlook.com/powershell-liveid?DelegatedOrg=$($customerId)&BasicAuthToOAuthConversion=true" -Credential $credential -Authentication Basic -AllowRedirection
Import-PSSession $session -allowclobber -Disablenamechecking
$Mailboxes = Get-Mailbox | Get-MailboxStatistics | Select-Object DisplayName, @{name = "TotalItemSize (GB)"; expression = { [math]::Round((($_.TotalItemSize.Value.ToString()).Split("(")[1].Split(" ")[0].Replace(",", "") / 1GB), 2) } }, ItemCount | Sort "TotalItemSize (GB)" -Descending
foreach ($Mailbox in $Mailboxes) { if ($Mailbox.'TotalItemSize (GB)' -gt $SizeToMonitor) { $LargeMailboxes += $Mailbox } }
Remove-PSSession $session
}
if (!$LargeMailboxes) { "No Large mailboxes found" }
Single Tenant Script
$ApplicationId = 'xxxx-xxxx-xxx-xxxx-xxxx'
$ApplicationSecret = 'TheSecretTheSecrey' | Convertto-SecureString -AsPlainText -Force
$TenantID = 'YourTenantID'
$RefreshToken = 'RefreshToken'
$ExchangeRefreshToken = 'ExchangeRefreshToken'
$upn = 'UPN-Used-To-Generate-Tokens'
$customertenant = 'CustomerTenant.onmicrosoft.com'
$SizeToMonitor = 60
$credential = New-Object System.Management.Automation.PSCredential($ApplicationId, $ApplicationSecret)
$aadGraphToken = New-PartnerAccessToken -ApplicationId $ApplicationId -Credential $credential -RefreshToken $refreshToken -Scopes 'https://graph.windows.net/.default' -ServicePrincipal -Tenant $tenantID
$graphToken = New-PartnerAccessToken -ApplicationId $ApplicationId -Credential $credential -RefreshToken $refreshToken -Scopes 'https://graph.microsoft.com/.default' -ServicePrincipal -Tenant $tenantID
Connect-MsolService -AdGraphAccessToken $aadGraphToken.AccessToken -MsGraphAccessToken $graphToken.AccessToken
$LargeMailboxes = @()
write-host "Getting Large mailboxes" -ForegroundColor green
$token = New-PartnerAccessToken -ApplicationId 'a0c73c16-a7e3-4564-9a95-2bdf47383716'-RefreshToken $ExchangeRefreshToken -Scopes 'https://outlook.office365.com/.default' -Tenant $customertenant
$tokenValue = ConvertTo-SecureString "Bearer $($token.AccessToken)" -AsPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential($upn, $tokenValue)
$customerId = $customertenant
$session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri "https://ps.outlook.com/powershell-liveid?DelegatedOrg=$($customerId)&BasicAuthToOAuthConversion=true" -Credential $credential -Authentication Basic -AllowRedirection
Import-PSSession $session -allowclobber -Disablenamechecking
$Mailboxes = Get-Mailbox | Get-MailboxStatistics | Select-Object DisplayName, @{name = "TotalItemSize (GB)"; expression = { [math]::Round((($_.TotalItemSize.Value.ToString()).Split("(")[1].Split(" ")[0].Replace(",", "") / 1GB), 2) } }, ItemCount | Sort "TotalItemSize (GB)" -Descending
foreach ($Mailbox in $Mailboxes) { if ($Mailbox.'TotalItemSize (GB)' -gt $SizeToMonitor { $LargeMailboxes += $Mailbox } }
Remove-PSSession $session
if (!$LargeMailboxes) { "No Large mailboxes found" }
And that’s it! as always, Happy PowerShelling.
Ps: I’m giving a new PowerShell webinar soon. Join me by clicking this link.
Kelvin Tegelaar
I am a Microsoft Certified System Engineer working as the CTO of the Managed Services Provider Lime Networks B.V. in the Netherlands. I mostly enjoy automating business processes by deploying PowerShell solutions, but just have a large passion for Microsoft Technology in general.
If you want to contact me directly you can find me on twitter here, or via email: Kelvin {at} limenetworks.nl
If you want to contact me directly you can find me on twitter here, or via email: Kelvin {at} limenetworks.nl
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