How SlaySlop checks Mail Configuration

I care how the check observes the signal: which DNS answers it reads, what "mail-routing" and "sender-policy" mean in public records, and how that evidence sits beside other domain findings.

SlaySlop's published definition: Mail configuration "Checks public mail-routing and sender-policy records." Public. Routing. Sender policy. I will not invent proprietary scoring the glossary does not state.

Outcome the check is for

You get findings or inventory context when public mail-routing or sender-policy records look missing, inconsistent, or otherwise noteworthy for a domain you are allowed to assess. The outcome supports delivery and impersonation-risk conversations with evidence from DNS, not from a single test message you happened to receive.

Domain insights lists included checks: DNS records, DNSSEC, WHOIS, Mail configuration, Redirect chain, Open ports, Subdomains (product page inventory). Workflow copy: resolve the domain, check transport, map public records including mail config, keep infrastructure beside findings.

Boundaries

Read-only public records. Permission required for client work. Not a pentest. Not an ESP reconfiguration service. SlaySlop does not edit the zone. Private records and mailbox ACLs stay out of scope.

DNS records collection is the broader public inventory. DNSSEC is signing. WHOIS is registration signals. Mail configuration is the mail-routing and sender-policy focus. Mixing them produces useless tickets.

Happy path: how the signal is observed

Domain insights framing: insights come from the public surface of the domain; no agent or install needed; context stays linked to findings; rescan catches when public configuration shifts.

When I reproduce:

# Permissioned
dig example.com MX +short
dig example.com TXT +short
# Look for SPF and DMARC-related TXT policy records as published publicly
dig _dmarc.example.com TXT +short

observer: public DNS
signal: mail-routing + sender-policy records
not_observed: inbox placement, SMTP AUTH, mailbox contents

Evidence should be the record data that triggered concern—the MX targets, policy TXT strings—as they appeared publicly—not a screenshot of someone's Gmail.

Pitfalls when reading the check

Treating a personal successful email as proof of domain policy. Forgetting sibling domains or send subdomains. Ignoring that SPF mechanisms can look "present" while including dead vendors. Assuming DKIM selectors you do not query are fine because MX points at a big brand.

Depth notes

Engineering hygiene: store the dig output with the ticket. Mail arguments without record text become folklore by Thursday. Rescan after ESP migrations; Domain insights explicitly calls out catching public configuration shifts.

Expansion

How I annotate evidence for humans

Raw dig lines are enough for engineers and opaque for clients. I paste the record, then one plain sentence: "MX points at vendor A while the contract says vendor B," or "DMARC is missing on the apex used in From headers." Mail configuration findings should survive a non-technical read without losing the public-record proof.

evidence_block:
  record_type: MX|TXT|DMARC
  name: example.com
  value: (public string)
  why_it_matters: spoof risk|delivery blackhole|vendor drift

Relationship to monitoring after go-live

Uptime monitoring will not notice an SPF include that grew too large. Scheduled domain rescans will. Domain insights product language about catching public configuration shifts is the operational hook: put a human on the diff when mail vendors change.

Related next step

Read Mail configuration next to DNS records and DNSSEC on the same domain view. SlaySlop keeps those infrastructure signals together.