By Default Exchange (ergo Outlook) Will Move Deleted Items To Recoverable Items 30 Days From Date Of Deletion - 14 Days Later Those Items Are Gone For Good
You can change the recoverable items retention time by following these "simple" PowerShell commands...
What is PowerShell?
PowerShell is a task automation and configuration framework developed by Microsoft, made from a command-line windows and a scripting language. Windows 10 closely aligns it's functionality to this language.
What Can I Do With It?
The simple answer is almost anything you can think of. For example you could create a report of all the USB devices installed on your PC, perform your favourite CMD tasks, kill a process in PowerShell rather than in Task Manager, change permissions on folders/drives.
Increase Recoverable Items Deletion Time From 14 Days to 30 Days
Open PowerShell as an Administrator on your PC [search for it]
Set-ExecutionPolicy RemoteSigned [sign in to 365]
$UserCredential = Get-Credential [sign in as global admin user]
install-module MSOnline [just in case this module is not available]
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection [connects to the Exchange admin centre, specific module] Import-PSSession $Session -DisableNameChecking [imports the commands from EXO to PowerShell]
Get-Mailbox -ResultSize unlimited -Filter {(RecipientTypeDetails -eq 'UserMailbox')} | Set-Mailbox -RetainDeletedItemsFor 30 [set the retention time to 30 days]
[Check its working!]
Get-Mailbox -ResultSize unlimited -Filter {(RecipientTypeDetails -eq 'UserMailbox')} | Format-List Name,RetainDeletedItemsFor