Email Marketing Automation Checklist for Web Development

Standardize fields like user_id, email, locale, plan_tier, last_active_at, and consent_status using dbt models with tests for not null, unique, and accepted values. A stable schema reduces mapping errors when syncing audiences to your ESP.

Capture signup, activation milestones, billing, and feature usage with Segment or RudderStack and validate payloads via Zod or Pydantic. Strong typing prevents malformed data from breaking trigger-based sends.

Use Hightouch or Census to push warehouse segments and custom fields into Mailchimp, SendGrid Marketing Campaigns, or Iterable. Schedule near real-time jobs for lifecycle email timeliness while respecting ESP rate limits.

Wrap ESP API calls in a worker (BullMQ, Sidekiq, or Celery) using idempotency keys per user-campaign and exponential backoff on 429/5xx. Deduplicate by message hash to prevent double sends during deploys or restarts.

Verify signatures for SendGrid, Mailgun, or Postmark webhooks, then persist events to Kafka/SQS and update suppression lists in your DB. Store raw payloads for auditability and downstream analytics joins.

Use AWS Secrets Manager or Vault for ESP keys, rotate regularly, and enforce separate credentials for dev/staging/prod. Prevent staging from emailing real users by defaulting to a sink SMTP or sandbox mode.

Extract headers, footers, CTAs, and content blocks into versioned MJML components with tokens for colors and spacing. Compile in CI to responsive HTML and reduce boilerplate across campaigns and newsletters.

Render emails using Handlebars, Liquid, or Nunjucks with TypeScript interfaces for context objects. Implement helpers for date formatting, pluralization, and markdown-to-HTML, and sanitize untrusted strings.

Store subject lines, preview text, and body variants in JSON/YAML backed by Git. Expose an internal service that serves variants by experiment_id for A/B tests and personalized sequences.

Intercept emails in dev via a local SMTP sink and generate snapshots with Jest or Playwright for key templates. Catch layout regressions early and speed up code review.

Use i18next or FormatJS to manage message catalogs, pluralization, and right-to-left layouts. Validate missing keys during build and default to a safe English fallback.

Gate optional sections (e.g., upgrade nudges or changelog cards) behind JSON metadata or LaunchDarkly flags. Render defaults when a trait is null to avoid broken layouts.

Model onboarding, activation, power users, churn risk, and reactivation segments in dbt with SLA-labeled freshness. Keep logic in code to enable pull requests and reviews.

Stream events via Kafka, Kinesis, or EventBridge to serverless functions that call transactional APIs within seconds. Use circuit breakers and dead-letter queues to avoid lost sends.

Provide topic-level opt-ins, double opt-in for some regions, and store legal basis, timestamp, and IP for GDPR/CCPA compliance. Sync preferences back to the ESP reliably.

Check for missing first_name, plan, and last_feature_used before rendering; fall back to neutral copy and generic CTAs when data is absent. Prevent broken personalization in production.

Generate recommendations from usage heuristics or a simple logistic model stored in a feature store. Show contextually relevant tips or docs links in sequences without overfitting.

Use Redis counters to enforce per-user daily/weekly caps across campaigns and elevate transactional emails above marketing. Reduce fatigue while protecting critical sends.

Test rendering with minimal, full, and edge-case contexts, and assert required fields with tsd or JSON Schema. Track coverage to avoid gaps when refactoring templates.

Leverage SendGrid or Postmark sandbox to validate payloads and webhooks. Seed staging with anonymized, production-like fixtures to uncover data shape issues early.

Precompute sample sizes from baseline open and click rates, and run fixed-horizon or sequential tests to avoid peeking bias. Assign variants server-side and persist bucketing.

Randomly exclude a small percentage of eligible users from campaigns to estimate true lift. Log assignments to BigQuery or Snowflake for downstream analysis.

Append UTM parameters consistently and capture them on landing pages. Join email engagement to product events in Looker, Metabase, or Amplitude to quantify outcomes.

Expose send volume, latency, hard/soft bounces, and complaint rates via Prometheus/Grafana. Alert on deviations from baselines with PagerDuty or Opsgenie.

Publish DNS records, verify DKIM for each sending domain, and ramp DMARC from p=none to p=reject with aggregate reports via dmarcian or Postmastery. Enforce TLS with MTA-STS where supported.

Sync hard bounces, complaints, and unsubscribes between your DB and ESP, and dedupe recipients by normalized email hash before enqueueing. Prevent policy violations and wasted sends.

Gradually increase volume and set rate limits per domain (e.g., Gmail, Outlook) based on provider guidance. Monitor reputation signals and adjust ramps automatically.

Use semantic HTML, sufficient color contrast, descriptive ALT text, and test dark mode color tokens. Validate across Outlook, Gmail, and Apple Mail with Litmus or Email on Acid.

Avoid including secrets or sensitive PII in emails, encrypt click logs at rest, and apply strict data retention. Use short-lived signed links for account actions where possible.

Document pipelines and failure modes with architecture diagrams and ADRs, enforce CODEOWNERS on template and workflow changes, and add pre-commit linting for MJML/HTML.