On Tue, 29 May 2018, Alexander Wirt wrote:
<freewx-maint@lists.alioth.debian.org>: host alioth-lists-mx.debian.net[185.73.44.171] said: 550 Unrouteable address (in reply to RCPT TO command) your maintainer address is broken.
Yes, we're aware of that: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=899727