To cleanly handle double bounces:
1. Create a dot-qmail file at /var/qmail/mailnames/yourdomain.com/.qmail-doublebounce containing:
|exit 0
2. Route double bounces to this file:
echo yourdomain.com > /var/qmail/control/doublebouncehost echo doublebounce > /var/qmail/control/doublebounceto
