On Mon, Nov 14, 2022 at 12:33:02PM -0700, Bryan Arenal <b.are...@gmail.com> wrote:
> Hi there, > > Is Postfix capable of checking DKIM and SPF records on incoming email > and adding headers based upon its findings? For example, an email > with a valid DKIM signature shows these headers sent to O365: > > ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass > smtp.mailfrom=example.com; dmarc=pass action=none header.from=example.com; > dkim=pass header.d=example.com; arc=none > > My google searches have only returned results on how to do DKIM > signing on outbound email and not how to verify them on inbound > emails. > > Thanks! That "ARC-Authentication-Results" header is actually ARC, not DKIM/SPF (i.e. a meta-DMARC for forwarders that modify what is being forwarded). I don't know what can create those headers. OpenARC seems defunct. I think OpenDMARC checks ARC headers (as well as DMARC/DKIM/SPF) and adds "Authentication-Results" headers. rspamd probably does it as well. There's a tutorial on adding OpenDMARC to postfix on Debian here: https://www.linuxbabe.com/mail-server/opendmarc-postfix-debian It's for debian but there might be equivalent tutorials for other Linux systems on that website. It might assume other steps in the complete tutorial: https://www.linuxbabe.com/mail-server/build-email-server-from-scratch-debian-postfix-smtp But maybe not. People say good things about rspamd as well. Check that out. cheers, raf
