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). Substack starts at free versus $17/mo for Mailjet. Both offer free plans to get started. Mailjet has the edge with marketing automation, A/B testing, SMS marketing.
Quick Verdict
Mailjet wins on integrations.
Substack wins on price, 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 | $17/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 | ✓ | ✕ |
| A/B Testing | ✓ | ✕ |
| Landing Pages | ✕ | ✕ |
| Segmentation | ✓ | ✕ |
| Drag & Drop Editor | ✓ | ✕ |
| SMS Marketing | ✓ | ✕ |
| Ecommerce Features | ✕ | ✕ |
| API Access | ✓ | ✕ |
| Multi-Language | ✓ | ✕ |
| Web Push Notifications | ✕ | ✕ |
| Live Chat | ✕ | ✕ |
| Advanced Analytics | ✓ | ✕ |
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% | $17/mo | Free |
| Deliverability | 25% | 88% | 95% |
| Rating | 25% | 4/5 | 4.4/5 |
| Integrations | 10% | 110 | 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 A/B testing
Choose Substack if…
- + You want lower starting costs (Free)
- + You're a independent writers and journalists
- + You're a newsletter creators monetizing through paid subscriptions