The roundtrip probe kept failing after the SPF/MX fix: rspamd's actual
junk-score driver was R_DKIM_PERMFAIL(+4.5) on selector brevo2 — Brevo
signs with brevo1/brevo2._domainkey, which are CNAMEs to
b{1,2}.viktorbarzin-me.dkim.brevo.com in public DNS and were absent
from the internal zone (the earlier existence check used ANY queries,
which Cloudflare refuses per RFC 8482 — false negative). The DKIM
permfail also cascaded into DMARC_POLICY_SOFTFAIL(+1.5), totalling the
6.09/6.0 junk threshold; sieve filed probes into \Junk where the INBOX
poll never finds them.
ingress-dns-sync now maintains both selector CNAMEs. Ops notes: rspamd
caches DNS (restart to flush after zone fixes); CoreDNS denial cache
holds NXDOMAINs up to 300s. Verified: roundtrip SUCCESS in 20.5s.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>