Postmark

Postmark is the transactional email service that B2B SaaS companies pick when the cost of a missing email is real revenue. It is built around a simple idea: transactional mail and broadcast mail are different products, run them on different streams, and your password resets stop competing with your marketing newsletter for sender reputation.

What Postmark Does

Postmark is a hosted email API plus SMTP relay, focused on transactional delivery for product and engineering teams. It has been in market since 2010, runs separate infrastructure for transactional and broadcast traffic, and publishes live deliverability numbers across the major inbox providers.

• Email API and SMTP: send via REST, the Bulk API, or SMTP, with libraries for Node, Ruby, Python, PHP, .NET, Go, Java, and more.
• Message Streams: dedicated transactional and broadcast streams on separate IP pools, so promotional sends cannot harm transactional deliverability.
• Templates: responsive, pre-tested templates with versioning and a layout system, so designers and marketing can ship copy changes without a deploy.
• Webhooks and Message Events: granular events for delivery, bounce, spam complaint, open, click, and subscription change, pushed to your stack in real time.
• Inbound Email: parse replies and forwarded mail into structured JSON, so customer responses flow into your CRM, support tool, or n8n workflows automatically.
• 45 days of full content history (extendable to 365) for every message, so support and engineering can audit exactly what was sent, to whom, and when.
• Rebound, the built-in bounce handling tool that surfaces blocked addresses and helps you keep lists clean before deliverability suffers.

Postmark's AI and Developer Tooling

Postmark's recent push has been around AI Skills, a way to teach AI coding agents how to send email through Postmark without hand-rolling SMTP logic. That matters as more teams build agentic features into their products. Combined with strong SDKs, message events, and a clean webhook model, Postmark behaves more like infrastructure than a marketing app, which is what engineering teams actually want.

Automations We Build with Postmark

Postmark only earns its keep if the surrounding system actually talks to it. We treat it as the delivery layer and build the orchestration around it, so the right events trigger the right messages and the right people get notified when something breaks.

• Stream split-out: audit every transactional send, separate it from broadcast traffic, and move the right messages onto Postmark's transactional stream so sender reputation stops being a coin flip.
• Event-to-email pipeline: wire Supabase, Stripe, your backend, and n8n into Postmark so user actions trigger the right template in the right language, with the right unsubscribe behaviour.
• Deliverability dashboard: pipe Postmark message events into a warehouse (BigQuery or Postgres) and build a single view of bounce rate, complaint rate, open rate, and inbox placement per stream and per template.
• Bounce and complaint automation: route hard bounces and spam complaints back into your user database, suppress them automatically, and notify the right team in Slack when an account is at risk.
• Inbound parsing into the CRM: catch replies to support@ or billing@, parse them with Postmark inbound, and create or update records in HubSpot, Attio, or ClickUp without anyone copying and pasting.
• Template governance: move templates into Postmark with versioning, set up a staging stream for review, and give marketing edit access without giving them production keys.
• Migration off SendGrid, Mailgun, or SES: dual-send during cutover, verify delivery numbers, and only flip DNS once the new stack is measurably better.

Why Teams Choose Postmark

• Deliverability is the product. Sender vetting is strict, transactional and broadcast traffic sit on different IP pools, and public delivery times are published per inbox provider.
• Visibility engineers actually use. Forty-five days of full content history (up to 365 on higher plans), message events, and a search-friendly activity feed make debugging a missing email a five-minute job, not a ticket.
• Pricing that does not punish growth. Free tier covers testing, paid plans start at $15 per month for 10,000 emails, with per-1,000 overage rates well under most competitors.
• Support that answers like humans. Postmark publishes an 86% customer happiness rating, with email, chat, and one-to-one calls available across plans rather than gated behind enterprise pricing.
• Compliance ready. GDPR compliant out of the box, with EU data residency, DKIM and SPF tooling, and SOC 2 controls suitable for B2B SaaS buyers who care about how their customer data is handled.

Postmark connects natively to Supabase, Stripe, HubSpot, Salesforce, Segment, n8n, Zapier, and almost any backend that can sign a POST request. Pricing starts free for 100 emails per month, then $15 per month at 10,000 emails on Basic, $16.50 on Pro, and $18 on Platform, with custom volume pricing above that. We build the automations, deliverability monitoring, and event pipelines that turn Postmark from a sending API into your transactional email system. That is the build we do.