Open-source alternative
for Postmark
Everything Postmark offers for transactional emails, plus marketing campaigns, workflow automation, and segmentation. One platform, no extra cost.
One Platform for All Your Emails
Transactional reliability meets marketing power
Transactional + Marketing
Reliable transactional emails plus marketing campaigns, workflows, and segmentation in one platform.
Transactional only
Excellent for transactional emails, but no marketing features. Need a second service for campaigns.
Why Choose Plunk Over Postmark
Do more with one platform instead of two
Marketing Campaigns Included
Send newsletters, announcements, and promotional emails without needing a separate marketing platform. One platform, one bill.
Workflow Automation
Build automated email sequences with triggers, delays, and conditions. Onboard users, nurture leads, re-engage customers. All automated.
Dynamic Segmentation
Segment your audience based on behavior, properties, and engagement. Send targeted emails to the right people at the right time.
Open Source & Transparent
AGPL-3.0 licensed. Inspect the code, contribute features, understand exactly how it works. No proprietary black boxes.
Self-Hostable
Run on your infrastructure with Docker. Full data control, compliance-ready, cost-optimized. Postmark is cloud-only.
Pay-As-You-Go Pricing
Simple per-email pricing with all features included. No separate charges for transactional vs marketing emails. No tiers, no commitments.
Feature-by-Feature Comparison
See exactly what you get with each platform
Frequently asked questions
What is the main difference between Plunk and Postmark?
Postmark focuses exclusively on transactional emails, while Plunk offers transactional emails plus marketing campaigns, workflow automation, and dynamic segmentation. Plunk is also open-source and self-hostable, giving you more flexibility and control.
Is Plunk as reliable as Postmark for transactional emails?
Yes. Plunk is built on AWS SES, which has excellent deliverability and reliability comparable to Postmark. Both support custom domains, DKIM authentication, and provide detailed delivery analytics. The key difference is Plunk adds marketing and automation features on top.
Can I use Plunk for just transactional emails like Postmark?
Absolutely. You can use Plunk purely for transactional emails just like Postmark. The marketing campaigns and workflows are optional features that are available when you need them, at no extra cost.
Why should I choose Plunk over Postmark?
Choose Plunk if you want transactional emails plus marketing capabilities in one platform. You get campaigns, automation, and segmentation without paying for a second service. Plunk is also open-source, so you can self-host or inspect the code.
How easy is it to migrate from Postmark to Plunk?
Migration is straightforward. Plunk's API is simple and well-documented. Update your application to use Plunk's API endpoints, configure your custom domain, and you're ready to go. Most migrations take a few hours.
Get more from your email platform
Stop juggling multiple tools. Get transactional reliability plus marketing power in one platform. Start free.