On Mon, Sep 20, 2010 at 4:10 PM, Jeroen Geilman <jer...@adaptr.nl> wrote:
> On 09/21/2010 12:07 AM, Curtis wrote: > >> In the case where transport_maps is used to designate the next hop >> destination of a message like this: >> >> customer.domain smtp:[mail.customer.domain] >> >> ...and the customer uses round robin dns for mail.customer.domain so that >> it points to multiple IPs like this: >> >> mail.customer.domain. 900 IN A 111.111.111.111 >> mail.customer.domain. 900 IN A 222.222.222.222 >> mail.customer.domain. 900 IN A 333.333.333.333 >> >> ....will postfix rotate between the ips that it delivers to? >> > > Yes. > > > Or, will it cache the first IP (111.111.111.111) and just deliver to that >> host until the next time postfix is reloaded >> > > No. > > > or the local DNS cache for the for mail.customer.domain expires? >> > > Yes. > > Also consider that that is not how a DNS cache works. > On the first query for that A record, all results are returned by an origin > server, and cached. > Postfix, too, gets all results from the cache. > Yes, this is how I understood it... that the local DNS would cache all three IPs... I just wasn't sure if Postfix might cache the first IP. But thanks to you and Victor, I am satisfied that it should work the way I hoped it would. Thanks, Curtis
