Don't attach new emails to closed cases

[VikinGDM]

Hi everyone!
I would like to suggest additional feature request

When a client writes a email support, very often he don't change the title of the email from the previous case.
When this email arrives, it is automatically linked by the old number to the old case.

if (preg_match('/\[#([0-9]+)[^0-9]*\]/', $email->get('name'), $m)) {
$caseNumber = $m[1];
$case = $this->entityManager
->getRDBRepository('Case')
->where([
'number' => $caseNumber,
])
->findOne(); 

I propose to add a setting to group mailboxes - excluding cases statuses. Then will remove the old number from the email header.
As example:

{ "type": "notin", "attribute": "status", "value": ["Closed"] }