tuleap.net is configured to accepts reply by mail via tokens. I received an artifact notification, tried to reply (message sent to forge__artifacts@tuleap.net), but got the following bounce:

Artifact with the title "Re: [request #8676] Tracker Performance Issue. Artifact retrievement takes 60 seconds" was not created. The tracker does not seem to have the create/reply by mail feature enabled.

This is in fact due to the fact that I reply to a mail sent to a mailing list, thus having no suitable headers for a reply-by-mail.

When Tuleap send an email to an unknown user (a mailing list for example), the Reply-to and/or the From headers MUST NOT BE "forge__artifacts@", they SHOULD BE "noreply@".