Email Parsing API Checklist for Financial Services

Catalog invoices, remittance advices, SWIFT MT/MX notices, ACH returns or NOCs, settlement reports, and chargebacks. Define extraction targets and delivery SLAs via webhook or REST to match downstream posting windows.

Map extracted fields to ERP or GL objects and mark PII or PCI data with retention rules. Standardize currencies with ISO 4217 and validate account formats such as IBAN or ABA routing numbers.

Use REST polling with short-lived tokens for locked-down bank networks. Prefer webhooks with HMAC signatures and source IP allowlists where outbound delivery is permitted.

Decide which headers, bodies, and attachments to store, hash, or redact. Replace PANs and SSNs with tokens and mask account numbers across payloads and logs.

Issue unique inbound addresses or subdomains per legal entity or client portfolio. Map each address to distinct webhooks and storage buckets to contain blast radius and simplify audits.

Record the legal basis for processing emails from EU or UK customers and link consent metadata to the email's Message-ID. Keep references accessible for regulatory inspections.

Require TLS 1.2+ with secure cipher suites and disable legacy protocols. Use mTLS or certificate pinning when mandated by bank policy.

Parse authentication results and attach them to the JSON payload for downstream fraud checks. Quarantine or reject messages failing DMARC to reduce spoofed invoice risks.

Decrypt encrypted statements or notifications using hardware-backed key storage with strict access controls. Audit every key operation per tenant and per Message-ID.

Scan headers, body, and attachments for SSN, PAN, IBAN, and routing numbers with checksum validation. Replace sensitive values with irreversible tokens before delivery.

Apply per-tenant envelope encryption to raw MIME and parsed JSON. Rotate keys regularly and record key IDs alongside storage records for audits.

Store hashed digests of raw MIME, webhook signatures, and parser versions in append-only logs. Align retention with SEC 17a-4 and FINRA books-and-records requirements.

Publish MX for a parsing-only subdomain and configure SPF to include authorized relays. Set DMARC policy to quarantine or reject to limit spoofing of financial notices.

Use aliases like ap-invoices@, chargebacks@, or swift-notices@ linked to specific parsers and webhooks. Enforce per-alias size and rate limits to protect capacity.

Filter by SMTP MAIL FROM, RFC5322 From, and DKIM d= domain for approved vendors and networks. Reject payment change requests from free-mail domains or high-risk TLDs.

Detect Auto-Submitted and List-* headers to exclude non-transactional messages from parsing. Route bounces and out-of-office notices to a quarantine queue.

Reject unknown executables and nested archives. For issuer PDFs that are password-protected, retrieve passphrases from a secure vault and log access events.

Record the full Received chain and convert timestamps to UTC while preserving originals. Keep RCPT TO and delivered-to values for accurate tenant routing and audits.

Expose Content-Type, Content-Transfer-Encoding, boundaries, and charset in the JSON envelope. Include Message-ID and In-Reply-To to support thread-aware finance workflows.

Support quoted-printable and base64 with charset handling for Windows-1252 or ISO-8859 families common in legacy banking systems. Fallback to UTF-8 with clearly logged substitutions.

Use templates for known vendors and heuristics for totals, due dates, remit-to, and invoice numbers when formats drift. Validate amounts and currencies against ISO 4217 codes.

Run OCR on image-only PDFs or TIFs and extract line items, fees, and taxes into normalized tables with correct numeric types. Restrict OCR to approved languages to reduce false positives.

Extract ACH return and NOC codes, SWIFT MT103 fields like 32A and 59, card chargeback reason codes, and settlement batch IDs. Emit strongly typed fields with clear code lists.

Verify invoice totals equal line items plus taxes and confirm IBAN or ABA check digits. Return structured error codes for mismatches to support automated exception handling.

Sign webhook payloads and include both a delivery ID and the email's Message-ID for deduplication. Expect 2xx within 5 seconds and perform safe retries on network errors.

Use exponential backoff with jitter and move repeated failures to a dead letter queue. Include last error and attempt counts in metadata for rapid triage.

Offer time-ordered cursors or watermarks to fetch new messages when webhooks are not allowed. Use short-lived OAuth or signed URLs with least-privilege scopes.

Allow targeted re-parse of a specific message or attachment after template updates, preserving the original raw MIME for reproducibility. Track parser version for each run.

Expose schema versions in headers and provide deprecation timelines that align with quarterly close cycles. Keep backward compatibility for critical financial fields.

Apply rate limits, burst buffers, and tenant-level quotas to handle statement and payroll spikes. Protect latency SLOs for high-priority financial documents.

Include invoices, bank statements, chargebacks, payment change fraud samples, DKIM edge cases, and large PDFs. Label expected fields and authentication outcomes for each sample.

Measure precision and recall for invoice total, currency, due date, account numbers, and remittance references. Define an error budget and gate releases on target attainment.

Verify redaction across headers, body, and attachments in both payloads and stored JSON. Block deployments if real PANs or SSNs appear in metrics or logs.

Track ingestion-to-delivery p50, p95, p99, parse failure rates, and DMARC failure ratio. Export metrics to your SIEM with tenant and use-case breakdowns.

Create playbooks for webhook failures, schema mismatches, and template regressions. Provide a replay tool that re-sends with the same idempotency key for safe recovery.

Export logs with cryptographic hashes, schema versions, and signature records. Enforce jurisdiction-specific retention and support legal hold without disrupting standard deletions.