Mailjet vs Substack
Mailjet is a email marketing platform while Substack is a newsletter platform. Mailjet has been around since 2010, giving it a 7-year head start over Substack (founded 2017). Mailjet starts at $9/mo, while Substack is free. Their pricing is not measured the same way, so we don't rank them on price. Both offer free plans to get started. Mailjet has the edge with marketing automation, A/B testing, landing pages.
Quick Verdict
Mailjet wins on integrations.
Substack wins on deliverability, rating.
Best for most users: Substack (independent writers and journalists).
Mailjet
Collaborative email platform for teams with powerful API
Mailjet is a French-founded email platform (now owned by Sinch) that uniquely combines transactional and marketing email under one roof with real-time team collaboration. Its volume-based pricing with unlimited contacts makes it particularly cost-effective for businesses with large subscriber lists but moderate sending frequency. With strong GDPR compliance baked into its European DNA and a flexible API, it bridges the gap between developer-focused tools and marketer-friendly platforms.
Substack
The newsletter platform where writers build independent media businesses
Substack is the dominant newsletter platform that uniquely combines free publishing tools with a 10% revenue-share model, letting writers launch subscription-based media businesses with zero upfront cost. Beyond newsletters, it has evolved into a full creator ecosystem with podcasts, video, livestreaming, Notes (microblogging), and community Chat, backed by a powerful built-in discovery network that helps writers find audiences organically.
Feature Comparison
| Feature | Mailjet | Substack |
|---|---|---|
| Rating | 4/5 | 4.4/5 |
| Starting Price | $9/mo | Free |
| Free Plan | 6,000 emails/month (200/day), 1,000 contacts | Unlimited subscribers, unlimited emails, all core features free — Substack only charges when you earn |
| Founded | 2010 | 2017 |
| Email Templates | 70 | 1 |
| Integrations | 110 | 0 |
| Deliverability Rate | 88% | 95% |
| Marketing Automation | Yes | No |
| A/B Testing | Yes | No |
| Landing Pages | Yes | No |
| Segmentation | Yes | No |
| Drag & Drop Editor | Yes | No |
| SMS Marketing | Yes | No |
| Ecommerce Features | No | No |
| API Access | Yes | No |
| Multi-Language | Yes | No |
| Web Push Notifications | No | No |
| Live Chat | No | No |
| Advanced Analytics | Yes | No |
Mailjet: Pros & Cons
Pros
- + Real-time collaborative email editing lets multiple team members work on the same campaign simultaneously with live comments
- + Volume-based pricing with unlimited contacts means large lists stay affordable — one user grew from 0 to 50,000 subscribers affordably
- + Strong GDPR compliance built into the platform with EU data hosting, as a French-founded company under European regulations
- + RESTful API with SMTP relay supports both transactional and marketing email from a single platform
- + Deliverability rated 88% by EmailToolTester (above 83.1% industry average) with built-in list validation powered by Mailgun
Cons
- − Automation builder covers basics but lacks depth — triggers based on opens/clicks are tricky to configure and abandoned cart requires Zapier
- − No built-in landing page builder, forcing users to rely on third-party tools for lead capture
- − Many of the 110 integrations route through Zapier rather than being native direct connections
- − Migration from other ESPs is largely manual with limited import assistance for contacts, templates, and automations
- − Customer support response times are frequently criticized, with some serious technical issues going unresolved for extended periods
Substack: Pros & Cons
Pros
- + Completely free to start with no upfront costs — zero barrier to entry with all core publishing features available immediately
- + Built-in audience discovery network with Recommendations and Notes driving organic subscriber growth (users report gaining 1,000+ subscribers through Recommendations alone)
- + True content ownership: creators can export their full subscriber list and content at any time to migrate elsewhere
- + Multimedia platform supporting newsletters, podcasts, video, livestreaming, Notes, and Chat communities in a single integrated experience
- + Strong reader engagement with genuine community interaction through comments, Chat, and Notes — higher engagement rates than typical social media platforms
Cons
- − The 10% platform fee plus Stripe's ~2.9% + $0.30 per transaction creates a 13-16% total take rate that becomes very expensive at scale (e.g., $1,300-$1,600/month on $10K revenue)
- − No email marketing automation, segmentation, A/B testing, or advanced personalization — all subscribers receive identical emails with no conditional logic
- − No public API and zero native third-party integrations — cannot connect to CRMs, e-commerce platforms, Zapier, or other marketing tools
- − Limited design customization with a single standardized template — no drag-and-drop editor, no custom HTML, and minimal branding options
- − Platform can remove content or delete accounts without notice, and customer support is difficult to reach for issue resolution
The Verdict
Substack edges ahead with a 4.4/5 rating compared to Mailjet's 4/5. The gap comes mainly from deliverability (4.4 vs 3.5) and value for money (4.9 vs 4.4). On deliverability, Substack reports 95% compared to 88% for Mailjet — a meaningful difference if inbox placement is critical for your campaigns.
| Criterion | Weight | Mailjet | Substack |
|---|---|---|---|
| Starting Price | 30% | $9/mo | Free |
| Deliverability | 25% | 88% | 95% Winner |
| Rating | 25% | 4/5 | 4.4/5 Winner |
| Integrations | 10% | 110 Winner | 0 |
| Free Tier | 10% | Yes | Yes |
Weights determine how much each criterion counts toward the final score. See full methodology
Choose Mailjet if…
- + You need SMS marketing
- + You need marketing automation
- + You need API access for custom integrations
- + You need built-in landing pages
Choose Substack if…
- + You're a independent writers and journalists
- + You're a newsletter creators monetizing through paid subscriptions
- + Completely free to start with no upfront costs — zero barrier to entry with all core publishing features available immediately