Using multiple A records is good for performance balancing, but what if one of the systems fails? Using your cocnfiguration, the delivering mail server has an "a" record and a single MX, so it wouldn't try the other mail server in the case of a failure, right? Whereas, by listing multiple IPs and mx1/mx2, wouldn't the delivering mail server try the other address? Thanks, -Ben On Tuesday 25 October 2005 16:02, you wrote: > I once did this and it worked great: > > IN MX 10 mx.example.com. > > mx IN A 192.168.1.1 > IN A 192.168.1.2 > > ...etc. Perfect DNS load balancing. > > Jack > > Benjamin Smith wrote: > > >Currently, we have two mail relays for inbound messages, and a third for POP. > > > >The inbound messages go thru all the CPU-intensive anti-spam stuff, and then > >they relay it to the POP server for pickup. > > > >Currently, one of these is the "primary", and the other is "secondary", and > >I'd like them to be considered more or less as equals, since the "primary" > >system is getting beaten pretty hard. > > > >The DNS zone file says something like this: > > > >############################### > >@isp.com > ><SNIP> > > IN MX 100 mx1.isp.com. > > IN MX 1100 mx2.isp.com. > ><SNIP > >################################ > > > >I seem to recall that I make them act as "equals" by simply changing this to > > > >############################### > >@isp.com > ><SNIP> > > IN MX 100 mx1.isp.com. > > IN MX 100 mx2.isp.com. > ><SNIP > >################################ > > > >so that they both get about the same amount of inbound messages. Has anybody > >here actually done this? How well does this work as far as failover if either > >system fails? > > > >-Ben > >-- > >"The best way to predict the future is to invent it." > >- XEROX PARC slogan, circa 1978 > >_______________________________________________ > >CentOS mailing list > >CentOS at centos.org > >http://lists.centos.org/mailman/listinfo/centos > > > > > -- "The best way to predict the future is to invent it." - XEROX PARC slogan, circa 1978