Open-source alternative
for Mailjet
Mailjet is a solid email platform but locks you into monthly subscriptions and has no workflow automation. Plunk is open-source, self-hostable, pay-as-you-go, and includes automation — no second tool required.
The Pricing Model That Makes Sense
Pay for what you use, not fixed subscriptions
Pay per email sent
Pay-as-you-go pricing. Only pay for emails you actually send.
- ✓Only pay for emails you actually send
- ✓Scale up or down without commitment
- ✓Automation and marketing included
Monthly subscription plans
Tiered monthly plans based on email volume. Essential starts ~$17/month.
- Locked into monthly subscription tiers
- Pay for capacity whether you use it or not
- No workflow automation on any plan
What Plunk Adds
Beyond what Mailjet offers
Workflow Automation
Build multi-step email sequences with triggers, delays, and conditions. Onboarding flows, drip campaigns, re-engagement — Mailjet has none of this.
Dynamic Segmentation
Auto-updating audience segments based on contact data and behavior. Target campaigns with precision beyond Mailjet's basic list management.
Event Tracking
Track any custom event from your product and use it to trigger workflows or build segments. Connect your app's behavior to your email platform.
Open Source
AGPL-3.0 licensed. Inspect the code, contribute features, no vendor lock-in. Mailjet is a closed, proprietary platform.
Self-Hostable
Run on your own infrastructure with Docker. Full data sovereignty, compliance-ready, and you only pay AWS SES fees when self-hosting.
All-in-One Platform
Transactional, marketing, and automation under one roof. Pay-as-you-go for all of it — no separate tool for workflows.
Feature comparison
Frequently asked questions
When should I choose Mailjet over Plunk?
Choose Mailjet if you need inbox preview testing or built-in A/B testing for email campaigns. Mailjet has been around longer and has a broad feature set. Choose Plunk if you need workflow automation, want an open-source platform you can self-host, or prefer pay-as-you-go pricing without monthly subscription commitments.
What is the pricing difference between Plunk and Mailjet?
Plunk is pure pay-as-you-go at $0.001/email — you pay only for what you send. Mailjet uses monthly subscription tiers: their Essential plan starts around $17/month for 15,000 emails, scaling up from there. For variable sending volumes, Plunk is more cost-effective since you never pay for capacity you don't use.
Is migration from Mailjet to Plunk complex?
Migration requires updating your API integration since Plunk and Mailjet use different API structures. Core concepts (templates, webhooks, custom domains) map directly. Most teams complete the technical migration in a few hours. Contact lists and templates can be adapted with minimal effort.
What does Plunk offer that Mailjet doesn't?
Plunk adds multi-step workflow automation (triggers, delays, conditions — perfect for onboarding and drip sequences) and is fully open-source under AGPL-3.0, meaning you can self-host on your own infrastructure. Mailjet offers neither workflow automation nor self-hosting. Plunk also uses pure pay-as-you-go pricing rather than tiered subscriptions.
Try Plunk free
1,000 emails/month free. No credit card required. Add marketing and automation when you need it.