Thanks everybody for your quick answers! In summary, the debian.org mail server accepts "-" as local extension character, and it is documented in:
- https://wiki.debian.org/DebianServiceForDD#Step_4:_Setup_your_email - https://db.debian.org/forward.html (On my side, I did not manage to get the "+" to work). Have a nice week-end, Charles -- Charles Plessy Nagahama, Yomitan, Okinawa, Japan Debian Med packaging team http://www.debian.org/devel/debian-med Tooting from work, https://mastodon.technology/@charles_plessy Tooting from home, https://framapiaf.org/@charles_plessy