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
