Hello,
It appears that Hetzner has changed their bandwidth terms from "20 TB outgoing per month, then capped to 10 Mbit" to fully unmetered 1 Gbps connection on most servers:
https://wiki.hetzner.de/index.php/Traffic/en
Discussed at:
https://www.lowendtalk.com/discussion/152498/hetzner-dedicated-servers-now-w...
Adjust your relay bandwidth limits accordingly. :)