eMail send by "request tracker" can't be group in messagerie client


I try to deploy an instance of request tracker, and after some tunning the product is close to perfection.

But actually, mail send by request tracker cant be group by conversation in messagerie client (outlook).

The problem seems comming from mail headers “Thread-Topic:” and “Thread-Index:”

It is possible for request tracker to generate a value for those header? Or keep them from original request mail ?

Debian 11, RT 5.0.2 with postfix.