dmark by Kastro is the rebranded domain trust and sender evidence product now live at dmark.is. It helps organizations understand whether their email identity is configured, explainable, and safe to tighten.
The product focuses on SPF, DKIM, DMARC, BIMI, saved-domain evidence, DMARC report ingestion, sender attribution, recommendations, and protected-brand risk findings. The public promise is narrow by design: make domain authentication evidence understandable enough for security, operations, and management decisions.
Kastro uses dmark alongside advisory work when clients need a practical domain trust review, sender cleanup, DMARC policy path, or board-ready evidence around brand and email-authentication risk.
what we deliver.
SPF, DKIM, DMARC, and BIMI Checks
Check domain authentication posture and keep the result as evidence instead of losing it after a one-off lookup.
Saved Domain Evidence
Track domains, scan snapshots, DNS records, and posture changes so domain trust becomes a managed record.
DMARC Report Foundations
Build toward aggregate report ingestion, source inventory, unknown sender handling, and safer policy decisions.
Sender Attribution
Connect authentication results and report data to likely providers so legitimate and suspicious sources can be separated.
Brand Risk Findings
Turn domain and sender signals into explainable findings for management, security, and operations teams.
Founder-Led Onboarding
Scope dmark onboarding around real domains, known senders, current DNS records, and the decisions the client needs to make.
real-world scenarios.
Domain Trust Review
A company wants to know whether customers can trust email from its business domains and whether the current authentication setup matches reality.
dmark frames SPF, DKIM, DMARC, BIMI, saved-domain evidence, and practical next steps in one evidence-backed workflow.
Sender Evidence Cleanup
Marketing, CRM, invoicing, Microsoft 365, and other systems all send mail, but nobody has a reliable sender inventory.
dmark supports sender attribution and evidence gathering before stricter DMARC enforcement decisions are made.
Brand Risk Pilot
Leadership needs explainable domain and brand-risk findings, not just raw DNS output or a vague warning.
Kastro scopes a dmark-backed review around the domains, reports, and management-facing evidence that matter.
want stronger domain evidence?
Explore dmark by Kastro for email authentication, sender evidence, DMARC reporting, and brand-risk visibility.