We had a $user who deleted ALL emails from a shared mailbox and you might notice that the option to recover deleted items is grayed out and you cannot select it. We need to set a registry key to turn that option on. Key for 32-bit Outlook on a 32-bit version of Windows HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Exchange\Client\Options Key for 32-bit Outlook on a 64-bit version of Windows HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Exchange\Client\Options Key for 64-bit Outlook on a 64-bit version of Windows HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Exchange\Client\Options Create a new DWORD value with the name ‘DumpsterAlwaysOn’ and a value of 1. Easy via PowerShell: if(!(test-path "HKLM:\SOFTWARE\Wow6432Node\Microsoft\Exchange\Client\Options")){ New-Item -Path "HKLM:\SOFTWARE\Wow6432Node\Microsoft\Exchange\Client" -Name 'Options'$props = @{
# Pick the right path for your OS and Office Version
path         = "HKLM:\SOFTWARE\Wow6432Node\Microsoft\Exchange\Client\Options"
name         = 'DumpsterAlwaysOn'
value        = '1'
propertytype = 'DWORD'
force        = $true verbose =$true
}

New-ItemProperty @props
}else{
$props = @{ # Pick the right path for your OS and Office Version path = "HKLM:\SOFTWARE\Wow6432Node\Microsoft\Exchange\Client\Options" name = 'DumpsterAlwaysOn' value = '1' propertytype = 'DWORD' force =$true
verbose      = \$true
}

New-ItemProperty @props
}

You have to close Outlook and start it again and voila, you can restore items.