How do I setup one secondary MX for two primary mail server? The two main ones have different domains and settings. All three are postfix.
Thank you. November 23, 2022, 10:07 AM, "raf" <post...@raf.org> wrote: > > On Sun, Nov 20, 2022 at 12:04:34PM +0100, Benny Pedersen <m...@junc.eu> wrote: > > > > > linux...@gmx.net skrev den 2022-11-20 09:49: > > > > when secondary MX server forwards messages to primary MX, how can I > > setup SPF policy to make them not breaking SPF? > > > > "v=spf1 mx -all" :) > > > > all other variants is just more verbose > > > > I think it's more polite to use actual IP addresses so > as to eliminate a DNS lookup. They take time, and there > is a limit to the number of DNS lookups that an SPF > checker will perform. Also, if you need to include: > another domain's SPF record, that might incur more DNS > lookups beyond your control, so the fewer you impose, > the better. > > So, yes, it's more verbose, but it's also more efficient. > > Also, using "mx" isn't great if you have more than one > MX host, and only the primary one sends mail. It's > probably harmless, though, as long as you control all > the MX hosts. > > cheers, > raf >
