Exchange 2010 get list of mailboxes with logon time information

Below you can find script which will return all mailboxes where LastLogonTime is older than 90 days ago.

You can easly set this date in variable $days.

Function New-Array {,$args}
$Report = New-Array

$days = "90"

$date_last = (Get-Date).AddDays(-$days) 
$mailboxes = Get-Mailbox -server mxmbx01 -ResultSize unlimited

foreach($mailbox in $mailboxes) 
{ 
  $mbx_DN = $mailbox.DistinguishedName 
  $email = $mailbox.PrimarySmtpAddress.toString()
  $Stat = Get-MailboxStatistics -Identity $mbx_DN | Where-Object {$_.lastLogonTime -lt $date_last} | Select-Object DisplayName, totalitemsize,LastLogonTime

 if ($Stat){
  $tmp = New-Object System.Object
  $tmp | Add-Member -type NoteProperty -name DisplayName -value $($stat.DisplayName)
  $tmp | Add-Member -type NoteProperty -name Email -value $email
  $tmp | Add-Member -type NoteProperty -name TotalSize_MB -value $($stat.TotalitemSize.value.ToMB())
  $tmp | Add-Member -type NoteProperty -name LastLogon -value $($stat.LastLogonTime)
  $Report += $tmp
 }
}
$Report | Export-Csv D:\Scripts\lastlogon_report.csv

As a result of this script, you will get .csv file, with informations DisplayName, email address, size of mailbox in MB, and last logon time.