PowerShell script to get the Total Item Size of an Exchange mailbox database

Get-TotalItemSize.ps1

$Date = Get-Date -UFormat %Y%m%d
$FileName = "TotalItemSizeReport" + $Date + ".csv"
$DbList = (Get-MailboxDatabase | select Name -ExpandProperty Name | Sort-Object) #Query a list of all databases and sort it.
$SizeTable = @{} #Define an empty hash table.
foreach ($Db In $DbList)
{
    $TotalItemSize = (Get-MailboxStatistics -Database HQMB1DB1 | ForEach-Object {$_.TotalItemSize.Value.ToBytes()} | Measure-Object -Sum).Sum/1GB
    $SizeTable.Add($DB,$TotalItemSize) #Add content to the hash table.
}
$SizeTable.GetEnumerator() | Sort-Object -Property Name | Export-Csv "\\Server\Path\$FileName"
Send-MailMessage `
    -From "sender@domain.com" `
    -To "recipient@domain.com" `
    -SmtpServer "smtpserver.domain.com" `
    -Subject "Exchange DB Total Item Size Report" `
    -Body "Please find the total item size report for all the Exchange databases attached." `
    -Attachments "\\Server\Path\$FileName"