Sigil

Sigil turns report attachments in an IMAP mailbox into a view of how a domain’s mail is authenticated. Sending sources, alignment failures, and TLS delivery problems can be reviewed together.

What it does

• Ingests compressed XML and JSON attachments for DMARC aggregate reports and SMTP TLS reports.
• Shows pass rates, timelines, sending sources, and domain summaries to help distinguish spoofing from legitimate configuration problems.
• Checks MX, SPF, DKIM, DMARC, TLSA/DANE, MTA-STS, and TLS Reporting records.

Engineering

A FastAPI and PostgreSQL backend with a React frontend, packaged into one Docker image. Background polling handles ingestion, IMAP passwords are encrypted at rest, and migrations run on startup.

Source and access

MIT licensed and self-hosted. Repository screenshots render synthetic report fixtures; they do not expose mailbox contents or real sender data.