PowerShell: Get Mailbox Size for Members of Various AD Groups

One task that came up my first month at my current gig was to report on mailbox sizes for each member of various AD groups. Below is Exchange PowerShell script that I came up with.

#AD Setting for Multi Domain Forest
Set-ADServerSettings -ViewEntireForest $true

#Array for Reporting Objects
$Summary = @()

#Array of Requested Dept Codes Which Should AD Group Named After Them
$ADGroups = "Group1","Group2","Group3","Group4","Group5","Group6","Group7"

foreach ($ADGroup in $ADGroups)
{
#Pull AD Group Members
$dPart = (get-group $ADGroup).members

foreach ($dUser in $dPart)
{
#Get Mailbox Stats for Group Member
$mbstats = get-mailboxstatistics $dUser

#Only Report on Users with Actual Mailboxes
if($mbstats.TotalItemSize)
{
#Convert Size Into GBs
$mbsize = ("{0:N2}" -f ($mbstats.TotalItemSize.Value.ToMB()/1024))
#Create New PowerShell Object and Assign Data to It
$uEntry = new-Object PSObject
$uEntry | add-Member -memberType noteProperty -name "Display Name" -Value $mbstats.DisplayName
$uEntry | add-Member -memberType noteProperty -name "Mailbox Size (GB)" -Value $mbsize
$uEntry | add-Member -memberType noteProperty -name "Last Logon Time" -Value $mbstats.LastLogonTime
#Add Entry to Summary Array
$Summary += $uEntry
}

}

}

#Export Summary Info to CSV File
$Summary | Sort-Object {[int]$_."Mailbox Size (GB)"} -Descending | Export-CSV Mailboxes_By_AD_Group.csv -NoTypeInformation