# Reset-Dynquota
#
# Script to unto custom quotas on a usermailbox back to the database defaults
#
# Configure storage quotas for a mailbox
# https://technet.microsoft.com/en-us/library/aa998353(v=exchg.160).aspx 

param(
   $resultsize="unlimited",    # max mailboxes to read. Use "unlimited" for all. otherwise it i a test only
   $skipmbsize = 16GB,   # skip all mailboxes larger that size
   $csvresult = ".\reset-dynquota.csv"   # reportingfile
)

Write-Host "reset-Dynquota:Start"

Write-host "Set-ADServerSettings to ViewEntireForest "
Set-ADServerSettings -ViewEntireForest $true

Write-Host "Loading Mailboxlist" -NoNewline
$mblist = Get-mailbox -resultsize $resultsize | Select-Object timestamp,UserPrincipalName,UseDatabaseQuotaDefaults,ProhibitSendQuota,ProhibitSendReceiveQuota,IssueWarningQuota,SizeMB,Change
Write-host " Total $($mblist.count)"
foreach ($mailbox in $mblist) { 
   Write-host "Check $($mailbox.UserPrincipalName)" -nonewline
   $mbsize = (Get-MailboxStatistics -identity ($mailbox.UserPrincipalName)).totalitemsize
   $mailbox.SizeMB = $($mbsize.value.tomb())
   $mailbox.Timestamp = get-date -Format u
   Write-host " - $($mbsize.value.tomb())MB " -nonewline
   if ($mailbox.UseDatabaseQuotaDefaults) {
      $mailbox.change = "Unchanged"
      write-host "Unchanged" -foregroundcolor white
   }
   elseif ($mbsize -lt $skipmbsize) {
      set-mailbox `
         -Identity $mailbox.UserPrincipalName `
         -UseDatabaseQuotaDefaults:$true `
         -ProhibitSendQuota unlimited `
         -ProhibitSendReceiveQuota unlimited `
         -IssueWarningQuota unlimited
      $mailbox.change = "SettoDefault"
      write-host "SettoDefault" -foregroundcolor green
   }
   Else {
      write-host "SkipOverlimit" -foregroundcolor yellow
      $mailbox.change = "SkipOverlimit"
   }
}
$mblist | Export-Csv $csvresult -Append -NoTypeInformation
Write-Host "reset-Dynquota:Start"