If your business uses a custom email domain, attackers can abuse your brand long before anyone touches your network. Misconfigured SPF, DKIM, and DMARC records let spoofed email slip through, damage customer trust, and hide inside noisy mailbox reports nobody has time to read.
Kastro provides DMARC, DKIM, and SPF review so SMBs can see whether their domain is configured correctly. The paid tier turns raw email authentication reports into readable evidence: aggregated report summaries, sender inventory, alignment findings, and clear remediation guidance.
what we deliver.
Email Authentication Review
Check DMARC, DKIM, and SPF status for your custom domain so you know whether the basics are present, valid, and protecting your business email.
Premium Report Aggregation
Turn raw DMARC aggregate reports into a readable view of who is sending mail for your domain, which sources pass authentication, and where alignment is failing.
Sender Inventory
Identify the business systems sending mail for your domain, separate legitimate services from old configuration, and make ownership visible.
Change Notifications
Get a simple signal when report data shows new senders, authentication failures, or alignment changes that deserve review.
real-world scenarios.
Custom Domain Email Baseline
A small business uses Microsoft 365 with its own domain but has never checked whether SPF, DKIM, and DMARC are configured correctly.
Kastro verifies the records, prepares baseline reporting, and provides a clear checklist.
Safe DMARC Enforcement Rollout
An organization wants stronger protection but is afraid of breaking legitimate mail.
Kastro maps legitimate senders and guides the domain from monitoring to enforcement.