![](https://seccdn.libravatar.org/avatar/c8b49a7a57ae09cd5482d4a4ac5bb593.jpg?s=120&d=mm&r=g)
On 2020-02-25 21:20, Dave Howorth wrote:
And some recipient's mailservers (presumably my ISP?) who bother to check for such things consequently discard it as from the wrong source?
That's the whole point of Sender Policy Framework (spf)
If so, surely the list server should remove the SPF record before forwarding the message, and perhaps add one of its own?
You got it all wrong. It's not included in the mail. It's part of DNS, and the mail server software (sendmail, postfix etc.) looks at it. If you look at he's (Pauls) mx domain you get mail.swabian.net. A check of the spf record gives: $ dig +short mail.swabian.net. TXT "v=spf1 a -all" The records are interpreted from left to right. v = version a = allow sending mail from the DNS a-record -all = reject all mail coming from hosts other than the a-record. $ dig +short mail.swabian.net. 80.152.201.148 A starting point to read is Wikipedia. https://en.wikipedia.org/wiki/Sender_Policy_Framework There are significantly more complex spf-records. Here's Googles. $ dig +short google.com TXT "facebook-domain-verification=22rm551cu4k0ab0bxsw536tlds4h95" "docusign=05958488-4752-4ef2-95eb-aa7ba8a3bd0e" "globalsign-smime-dv=CDYX+XFHUw2wml6/Gb8+59BsH31KzUr6c1l2BPvqKX8=" "docusign=1b0a6754-49b1-4db5-8540-d2c12664b289" "v=spf1 include:_spf.google.com ~all" $ dig +short _spf.google.com TXT "v=spf1 include:_netblocks.google.com include:_netblocks2.google.com include:_netblocks3.google.com ~all" $ dig +short _netblocks.google.com TXT "v=spf1 ip4:35.190.247.0/24 ip4:64.233.160.0/19 ip4:66.102.0.0/20 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:74.125.0.0/16 ip4:108.177.8.0/21 ip4:173.194.0.0/16 ip4:209.85.128.0/17 ip4:216.58.192.0/19 ip4:216.239.32.0/19 ~all" $ dig +short _netblocks2.google.com TXT "v=spf1 ip6:2001:4860:4000::/36 ip6:2404:6800:4000::/36 ip6:2607:f8b0:4000::/36 ip6:2800:3f0:4000::/36 ip6:2a00:1450:4000::/36 ip6:2c0f:fb50:4000::/36 ~all" $ dig +short _netblocks3.google.com TXT "v=spf1 ip4:172.217.0.0/19 ip4:172.217.32.0/20 ip4:172.217.128.0/19 ip4:172.217.160.0/20 ip4:172.217.192.0/19 ip4:172.253.56.0/21 ip4:172.253.112.0/20 ip4:108.177.96.0/19 ip4:35.191.0.0/16 ip4:130.211.0.0/22 ~all" -- /bengan -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org