Hello, I search how to do that client request about filter on mail reception :

1/ upon receipt of an email, send an automatic response and do nothing to classify the email that must remain in the inbox (thats it could be done with vacation sieve module)
2/ if the user sends a second email on the same subject, do not send a reply and leave it in the inbox
3/ if the user sends a new email on another subject we return to point 1

Thanks for you’re ideas