On 23 Sep 2014, at 15:31, Peer Heinlein <p.heinlein at heinlein-support.de> wrote: > > Using doveadm penalty I just noticed a penalty for 0.0.0.0. > > Is this Postfix querying the auth-socket for his SASL-requests? Most likely. 0.0.0.0 would in any case mean "unknown". It shouldn't show up in penalty though..