It appears that Alexander NAZARIAN via dmarc-discuss <alexander.nazar...@gmail.com> said: >So I want to understand whether having MX placed in the beginning of SPF >record can cause a quicker reach of '10 DNS lookup limitation' for G Suite >senders, due to the reason that G Suite has 5 MX records (and I assume that >number of DNS queries, executed to resolve MXes to IPs, is 6 and not 1)
I think he already answered that question. Different implementations of SPF interpret the counting rule differently, so if you want your mail delivered, assume that they will use the largest count. If you are checking else's mail, use the smallest count. This is the well known robustness principle about interpreting ambiguous specs. This particular case has not come up in the past because, in practice, the only sites that use "mx" are tiny sites with a single mail host with a single address. It doesn't make a lot of sense for secondary MX hosts to be sending mail for someone's domain. I also think that some of the advice about limits in 7208 is not very good. For example. you are likely to get different NOERROR counts evalating an ipv4 address than evaluating an ipv6 addresss since there are lots of hosts with A records but no AAAA. _______________________________________________ dmarc-discuss mailing list dmarc-discuss@dmarc.org http://www.dmarc.org/mailman/listinfo/dmarc-discuss NOTE: Participating in this list means you agree to the DMARC Note Well terms (http://www.dmarc.org/note_well.html)
