On Wed, Aug 02, 2017 at 02:47:27PM +0200, Christian Gut wrote: > > > On 2.Aug. 2017, at 14:09, Gilles Chehade <gil...@poolp.org> wrote: > > > > On Wed, Aug 02, 2017 at 01:47:09PM +0200, Kirill Miazine wrote: > >> * Eric Faurot [2017-08-02 13:24]: > >>> On Wed, Aug 02, 2017 at 11:44:47AM +0200, Christian Gut wrote: > >>>> Hi List, > >>>> > >>>> is it possible to have multiple relays (you might want to say smart > >>>> hosts) in smtpd? > >>>> > >>>> I currently use the following line: > >>>> > >>>> accept from local for any relay via smarthost.example.org > >>>> <http://smarthost.example.org/> > >>>> > >>>> Now I would like to have multiple smart hosts in there for backup > >>>> reasons, if one of the smart hosts is in maintainance. Is something like > >>>> this possible? > >>>> > >>>> accept from local for any relay via { smarthost1.example.org > >>>> <http://smarthost1.example.org/>, smarthost2.example.org > >>>> <http://smarthost2.example.org/> } > >>>> > >>>> Kind Regards, > >>>> Christian > >>>> > >>> It's not possible at the moment. There is ongoing work to support this > >>> feature, > >>> along with other improvements. But it's quite a big change, and we can't > >>> give an > >>> ETA right now. > >> > >> what about defining a new name in DNS containing addresses of all > >> smarthosts as a workaround for the OP for now? > >> > > > > This can work in some use-cases, this is exactly what a co-worker did to > > work around the limitation. > > How will smtpd operate then? Does it use the DNS records in a round robin > fashion or does it try them one after another if they fail? >
smtpd maintains states about its routes to a destination. what will happen is that it will resolve your relay hostname into all of its addresses and attempts to route to them. if a route is broken, it is marked as such for a small period and reattempted later, meanwhile there will be routes that aren't marked as broken and which smtpd will be able to use. -- Gilles Chehade https://www.poolp.org @poolpOrg
