Keep meeting invitation emails

I need to keep the meeting invitation email in my inbox, but accepting a meeting deletes it.
I haven’t been able to find an option to allow this.

(I use thunderbird as a client - I have tried

  • client side management (this keeps the email, but all responses to the organiser become “new time proposals” - silently, which doesn’t look professional, and is confusing as the same time as the original meeting is proposed
  • server side management - works fine for accept/decline, but can’t send an email reply (unrelated to the invite), and attachments aren’t accessible.

Outlook offers this option (calendar - Prevent Outlook from automatically deleting meeting emails - Super User), but axigen it seems doesn’t. I’m not able to rescue from “Deleted”/“Trash” either.

Thanks