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Version 4 of the Mailbox Size Gui and using Quotas in Mailbox Size Reports

Version 5 has now been posted that fixes issue with quotas please see this

Based on the feedback and requests I’ve received I’ve updated the Mailbox Size Gui to show the percent of Quota used by each user. While this was not hard to do it’s unfortunately not as simple as just pulling the information from the get-mailboxstatistics cmdlet. As I’ve shown in other posts before when you what to determine the Quota that applies to a user’s mailbox you need to check quota information in a number of locations. The first place you need to check is the users account to see whether then have the use store quotas defaults set to true of false. Within a Get-mailboxstatitics operation there is a property made available called UseDatabaseQuotaDefaults which can be used to do this. If this property returns false then the quota information will be set on the User's Mailbox itself (or more accurately the User object in Active Directory) so in this case you can use the Get-Mailbox cmdlet to retrieve the ProhibitSendReceiveQuota property on the user account. If the UseDatabaseQuotaDefaults is set to true the you need to find out which Mailstore the Mailbox is located on and then check the Mailstores quotas setting using the get-mailboxdatabase cmdlet. If you want to do this for a number of users you could pipleline it a few different ways the way I’ve chosen to do this in my Mailbox GUI script is to create 2 hashtables to store any MailStore and UserMailbox quotas and then during the get-mailboxstatisitics cmd use these Hashtables to determine the percent of Quota the user has actually used. Here’s a quick sample

$mstoresquotas = @{ }
get-mailboxdatabase -server servername | ForEach-Object{
if ($_.IsUnlimited -ne $true){


$usrquotas = @{ }
Get-Mailbox -server servername -ResultSize Unlimited | foreach-object{
if($_.ProhibitSendQuota -ne "unlimited"){

get-mailboxstatistics | ForEach-Object{
$quQuota = "unlimited"
if ($_.UseDatabaseQuotaDefaults -eq $false){
if ($usrquotas.ContainsKey($_.MailboxGUID)){
$quQuota = "{1:P0}" -f ($_.TotalItemSize.Value.ToMB()/$usrquotas[$_.MailboxGUID].Value.ToMB())
if ($mstoresquotas.ContainsKey($_.database)){
$quQuota = "{1:P0}" -f ($_.TotalItemSize.Value.ToMB()/$mstoresquotas[$_.database].Value.ToMB())}

What’s next when I get time I want to add a history feature so that every time you run the Gui it will record the result to an XML file so that the next time you run it in a week or months time it can then show you how much each mailbox has grown since. Also I’d like to come up with a cmd-line version that will output the result to a HTML Email with all the same functions. If anyone has any other idea’s they would like to see please let me know and I’ll see what I can do.

I’ve put a download of the new version here.

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All sample scripts and source code is provided by for illustrative purposes only. All examples are untested in different environments and therefore, I cannot guarantee or imply reliability, serviceability, or function of these programs.

All code contained herein is provided to you "AS IS" without any warranties of any kind. The implied warranties of non-infringement, merchantability and fitness for a particular purpose are expressly disclaimed.