The submitter will probably have to read the reply from the BTS web page. The mail system
<hramr...@centrum.cz>: host xmx2.centrum.cz[46.255.224.55] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org