Postmastery vs.
DMARC report viewer in 2026

In Postmastery, Microsoft 365 and Google Workspace were grouped as known corporate senders, while SendGrid and Mailchimp were separated enough for us to assign marketing ownership. The support desk sender landed in a review path rather than being hidden in raw IP volume, and the forwarded mail case was treated as an authentication edge case instead of a simple SPF failure. The spoof sample was visible as a policy risk, and the unknown sender became a classification task with enough context to hand to an application owner.

DMARC Report Viewer handled the XML aggregate files cleanly and gave us useful domain, reporter, source IP, and pass/fail views. Microsoft 365, Google Workspace, SendGrid, and Mailchimp were visible, but service naming depended on DNS, WHOIS, and source-IP lookups that we had to interpret. The DKIM pass on a subdomain was easy to inspect in the report details, while the unknown sender required a manual note outside the product.

For Postmastery, adding the corporate domain, marketing subdomain, and parked domain created a clear setup sequence: publish reporting records, confirm report flow, then classify senders. The unknown sender was findable through source drilldowns, and the forwarded mail SPF failure came with enough context to explain why the DKIM domain matched the visible domain and protected the message. The parked domain workflow was stricter, which helped us keep spoof risk separate from normal corporate mail.

For DMARC Report Viewer, the web UI was quick once the Docker instance and IMAP mailbox were working. The same three domains appeared in filters, but the product did not turn the unknown sender into an owner task, and the forwarded SPF failure looked like another failed row until we inspected DKIM and message disposition. This suited technical review, not cross-team handoff.

With Postmastery, our setup path assumed vendor involvement for onboarding, especially around confirming DNS records and preparing the first policy move. The DNS handoff notes were usable for an internal administrator, and escalation was clearer for the unauthorized spoof sample because the risk was tied to a parked domain. Enterprise onboarding felt structured, though pricing and package boundaries still needed a sales conversation.

With DMARC Report Viewer, support was the project documentation and the operating team's own ability to run the app. DNS setup was not managed, escalation meant opening our own issue path, and enterprise onboarding was not part of the product. That tradeoff was acceptable for a free self-hosted parser, but it slowed the handoff when a non-technical owner asked what to fix.

Postmastery handled account separation well enough for the corporate domain, marketing subdomain, and parked domain to stay distinct without making recurring reports hard to read. For an MSP, the handoff notes were useful, but the workflow felt more enterprise-led than high-volume client management. For an SMB, the service level and private pricing looked heavier than the problem unless enforcement risk is high.

DMARC Report Viewer was a better fit for an operator who wants one self-hosted place to inspect reports and export evidence. Account separation and client grouping were not native strengths in our test, so MSP handoff required separate documentation and naming conventions. SMB teams can use it at no software cost, but they need someone who understands DMARC domain matching and sender classification.