On Fri, 2026-09-04 at 23:31 +0200, Björn Persson wrote: > Adam Williamson wrote: > > fedoraproject.org 's looks like this: > > > > v=spf1 a a:mailers.fedoraproject.org ip4:38.145.32.11 ip4:38.145.32.12 ?all > > > > I'm not sure what the effect of the bare 'a' is (it might effectively > > mean 'pass for everything'). > > As that record is for fedoraproject.org, the bare "a" means the same as > "a:fedoraproject.org". It's a pass if the sending IP address is listed > in an A or AAAA record for fedoraproject.org.
Thanks. > > But as for the rest, it means the SPF > > result is a 'pass' if the sender IP has an 'A' record in > > mailers.fedoraproject.org domain, > > Or an AAAA record (although currently there are none). > > > Finally, DMARC is a kinda meta mechanism: it lets you tell recipient > > systems what you think they should do if mails fail any of the *other* > > checks. > > Not really, because it checks another thing than SPF does. SPF works > in the SMTP layer. It checks the envelope sender address and the "HELO" > identity. DMARC works in the Internet Message Format layer. It performs > SPF-like checks on the From header field instead. Well, the truth appears to be between the two. As the DMARC spec puts it: "SPF [RFC7208] can validate the uses of both the domain found in an SMTP [RFC5321] HELO/EHLO command (the HELO identity) and the domain found in an SMTP MAIL command (the MAIL FROM identity). DMARC relies solely on SPF validation of the MAIL FROM identity." So DMARC sort of includes a subset of SPF, I guess you could say. And technically, yes, the DMARC SPF check could pass but you could run the other kind of SPF check independently and it could fail, I guess. -- Adam Williamson (he/him/his) Fedora QA Fedora Chat: @adamwill:fedora.im | Mastodon: @[email protected] https://www.happyassassin.net -- _______________________________________________ devel mailing list -- [email protected] To unsubscribe send an email to [email protected] Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/[email protected] Do not reply to spam, report it: https://forge.fedoraproject.org/infra/tickets/issues/new
