Email to JSON Checklist for SaaS Platforms

List the exact fields downstream services require, including from, to, cc, subject, message_id, date, plaintext_body, html_body, and attachments. Lock a versioned schema so API consumers in your SaaS do not break with future changes.

Use webhooks for near real-time event-driven processing, and REST polling where strict firewall rules or burst control are required. Many SaaS platforms deploy both to support tenant variability.

Decide how tenants are identified in inbound emails, such as subdomains, plus-addressing, or custom headers. Tag JSON with tenant_id and route events through isolated queues for noisy-neighbor control.

Define targets for end-to-end latency (p95), parse success rate, and webhook delivery success. Tie alert thresholds to error budgets so on-call responders have clear action signals.

Decide on a consistent idempotency key, such as hash(message_id + recipient + received_date), to prevent duplicate records on retries. Store keys for a TTL that exceeds your maximum retry window.

Map where raw emails and derived JSON are stored and processed across regions. For regulated tenants, restrict storage to compliant regions and redact PII before persistence.

Use separated domains like inbound.example.com for prod and staging to avoid cross-environment leakage. Configure MX targets with high availability and short TTLs for failover.

Validate DKIM signatures and capture verification results in JSON to inform downstream rules. DMARC alignment signals can help triage spoofed messages in customer support or billing workflows.

Catch-all simplifies onboarding but risks misroutes, while explicit addresses offer tighter control. Reflect chosen strategy in your recipient parsing logic and JSON routing metadata.

Adopt plus-addressing like support+ticket123@example.com to bind messages to records. Extract tokens into structured JSON fields that your app can join on quickly.

Capture MAIL FROM and RCPT TO alongside header From and To in JSON. The envelope often reveals the real sender path and improves audit accuracy for SaaS admins.

Detect multipart/report, message/delivery-status, and common auto-reply patterns. Mark is_auto_reply and include parsed diagnostic codes so your workflow does not open duplicate tickets.

Prefer text/plain when available, else sanitize text/html to normalized text. Store both plaintext_body and html_body in JSON for maximum flexibility.

Normalize to UTF-8 and handle Content-Transfer-Encoding edge cases. Track original charset in JSON so downstream systems can debug mis-encoded messages.

Properly reconstruct long subjects and names that wrap across lines. Store canonicalized headers to prevent duplicate values caused by folding.

Populate filename, size, content_type, content_id, and disposition in JSON. Rewrite cid: references if you proxy images to a CDN for safe rendering.

Strip scripts and dangerous attributes while keeping links and lists. Provide both sanitized_html and plaintext_body to serve different UI needs in your SaaS.

Parse text/calendar and message/rfc822 as first-class elements with their own attachment entries. Expose event fields or nested headers in JSON to power scheduling and thread detection.

Emit structured arrays for from, to, cc, bcc with name and email properties. Include normalized lowercased emails alongside display names to simplify matching.

Store a headers map for audit use, and normalized fields like subject, date, message_id for quick access. This balances developer ergonomics with forensic depth.

Avoid embedding large binaries in JSON; store urls with integrity hashes and content_length. Include a retention policy flag so lifecycle jobs can purge blobs safely.

Map In-Reply-To and References, plus a computed thread_key derived from these headers. This helps your SaaS group messages and suppress duplicate notifications.

Include booleans like has_attachments, is_auto_reply, and is_external_sender. Precompute a text_preview and a safe_link_count to simplify UI rendering and risk scoring.

Mask secrets, tokens, and obvious identifiers before persistence, keeping a minimal JSON necessary for functionality. Track redaction_version for audit trails.

Compute an HMAC over the body with a per-tenant secret and include signature headers and timestamp. Reject requests that fail verification or are outside a short clock-skew window.

Send a stable idempotency_key header derived from message identity. Receivers should return 2xx on duplicates and remain side-effect free.

Retry non-2xx responses with jitter, escalating to a DLQ after a capped number of attempts. Expose DLQ replays per tenant to support self-serve remediation.

Require receivers to acknowledge within a small timeout and process heavy work asynchronously. This improves throughput and reduces retry storms across tenants.

Include a x-schema-version header and maintain backward compatibility windows. Provide a test endpoint so customers can validate upgrades before switching.

Allow secure replays by message_id, time window, or tenant scope. Require strong auth and audit logs to prevent data exposure across customers.

Collect anonymized samples that include tricky encodings, inline images, nested multiparts, and long subjects. Use them in CI to prevent parser regressions when you ship changes.

Inject malformed line endings, folded headers, and mixed charsets to ensure safe failure modes. Assertions should guarantee a valid JSON envelope even when parts are dropped.

Track ingestion latency, parse error rate, webhook success rate, and queue depth. Break down by tenant to detect misconfigurations and abusive traffic quickly.

Throttle by tenant and route to separate worker pools to protect shared infrastructure. Use circuit breakers to shed load gracefully under spikes.

Keep raw RFC 5322 messages short-term for reprocessing, and retain compact JSON longer for analytics. Tag records with retention_class so lifecycle policies are automatic.

Identify heavy hitters like HTML sanitization and attachment processing, caching where safe. Attribute costs to tenants to inform plan limits and upsell opportunities.