Postmark is a transactional email service built for developers and product teams who need fast, reliable delivery of critical app-generated emails like password resets, receipts, and account notifications. You integrate through a REST API, SMTP, or official libraries, then Postmark handles delivery, tracking, and analytics. Its Message Streams keep transactional and broadcast email strictly separated, protecting deliverability. Ideal for SaaS founders and engineering teams who want production-grade email infrastructure without building it themselves.

• Message Streams: Separate transactional and broadcast email onto isolated infrastructure so newsletter issues never affect password resets or receipts.
• REST API & SMTP: Clean API supporting up to 500 messages per call and 50 MB payloads, plus SMTP and official libraries for most major languages.
• Email Templates: Reusable templates with a visual editor and Mustachio templating language supporting variables, conditions, and loops.
• Inbound Email Parsing: Receive emails at Postmark addresses and get structured JSON posted to your app for reply-by-email and support flows.
• Webhooks & Analytics: Real-time webhooks for bounces, opens, clicks, and complaints, with searchable message history and per-stream dashboards.
• Deliverability Focus: Guided SPF, DKIM, and DMARC setup plus actively monitored IP pools to keep inbox placement high.
• Dedicated IPs: Optional dedicated IP addresses on Pro and Platform plans for high-volume senders needing full reputation control.
• Fast Delivery: Postmark is built around fast transactional email delivery and reports 99%+ uptime and delivery rates.

• Excellent Deliverability: Users consistently report emails landing in inboxes after switching from SendGrid, Mailgun, and other providers.
• Long-Term Reliability: Multi-year customers report it "just works" without constant troubleshooting or attention.
• Transparent Analytics: Per-stream dashboards, webhook events, and searchable message history make debugging simple.
• Developer-Friendly API: Clear API documentation, official libraries, and straightforward integration make setup easier for development teams.

• Higher Cost at Scale: Postmark can cost more than alternatives such as Mailgun and SendGrid at higher sending volumes.
• Limited Marketing Features: No advanced segmentation, A/B testing, or marketing automation for teams needing full campaign tools.
• Very Small Free Plan: Free tier caps at only 100 emails per month, mainly useful for testing.
• Manual Account Approval: All new accounts require approval before sending, which can slow initial setup.
• No HIPAA Support: Postmark does not sign BAAs, so it can't be used to send Protected Health Information.

• SaaS Transactional Email: Send password resets, verification emails, account notifications, and other user-triggered messages from your application. Postmark specifically supports these types of transactional emails.
• E-commerce Order Flows: Deliver order confirmations, shipping updates, and invoices reliably with per-stream analytics to spot delivery issues before they hurt customer trust.
• Reply-by-Email Support: Use inbound parsing to accept customer replies as structured JSON and pipe them into your ticketing or support tool automatically.
• Developer Notifications & Alerts: Send system alerts, security notifications, and monitoring emails from internal tools using the REST API or SMTP.
• User Onboarding Sequences: Trigger welcome emails, trial reminders, and activation nudges from your app with templates that keep design consistent.
• Bounce & Suppression Management: Use bounce webhooks to receive real-time notifications, identify failed addresses, and stop sending to inactive recipients.