On Fri, 15 Sep 2017 07:52:49 +0200
Greg Kurz <groug@kaod.org> wrote:

> Dang! The mail relay at OVH has blacklisted Paul's address :-\
> 
> <paulus@samba.org>: host smtp.samba.org[144.76.82.148] said: 550-blacklisted at
>     zen.spamhaus.org 550 https://www.spamhaus.org/sbl/query/SBL370982 (in reply
>     to RCPT TO command)
> 

Dumb me! It's the opposite... OVH is blacklisted by smtp.samba.org :-\

Sigh.