Mailgun vs Substack

Detailed side-by-side comparison

Mailgun

Mailgun

Free

Mailgun is a developer-focused email API service built for transactional and marketing email infrastructure. It provides powerful email delivery, validation, and tracking capabilities with detailed analytics, making it ideal for applications that need programmatic email sending.

Visit Mailgun
Substack

Substack

Free

Substack is an all-in-one newsletter publishing platform designed for writers and content creators. It combines email delivery, website hosting, payment processing, and audience building tools into a simple platform that requires no technical knowledge.

Visit Substack

Feature Comparison

FeatureMailgunSubstack
Primary Use CaseTransactional and bulk email sending via API for developers integrating email into applicationsNewsletter publishing and content monetization for writers building a subscriber audience
Email Delivery MethodAPI-first approach with SMTP relay option, webhooks for real-time tracking, and programmatic sendingBuilt-in newsletter editor with simple interface for composing and scheduling email broadcasts
Customization & BrandingFull control over email templates, HTML/CSS customization, dedicated IP addresses for brand reputationLimited customization with basic templates and standardized Substack branding on free tier
MonetizationNo built-in monetization features; purely an email delivery infrastructure serviceIntegrated paid subscription model with automatic billing, payment processing, and revenue management
Analytics & TrackingAdvanced email analytics including open rates, click tracking, bounce analysis, and detailed delivery logsBasic subscriber analytics including opens, clicks, and subscription growth metrics
Technical RequirementsRequires development resources and API integration knowledge to implement and maintainZero technical knowledge needed; fully managed platform with web-based editor

Pricing Comparison

Both start at $0/month, but Mailgun charges based on email volume sent while Substack takes a 10% fee on paid subscriptions only. Mailgun scales with usage costs while Substack costs scale with revenue, making Substack free until you earn money but potentially more expensive as subscription income grows.

Verdict

Choose Mailgun if...

Choose Mailgun if you're a developer or company needing reliable email API infrastructure for transactional emails, automated notifications, or large-scale email sending with full technical control and customization.

Choose Substack if...

Choose Substack if you're a writer, journalist, or content creator looking to publish newsletters and build a paid subscriber base without technical complexity or upfront costs.

Get Your Free Software Recommendation

Answer a few quick questions and we'll match you with the perfect tools

1/4

Select the category that best fits your needs

Email Marketing

Pros & Cons

Mailgun

Pros

  • + Excellent deliverability rates and reputation
  • + Developer-friendly with comprehensive API documentation
  • + Robust email validation reduces bounce rates
  • + Flexible pricing based on volume

Cons

  • - Steeper learning curve for non-technical users
  • - Limited visual email builder compared to marketing-focused platforms
  • - Can become expensive at high volumes

Substack

Pros

  • + No upfront costs - only pays when you earn through 10% platform fee
  • + Extremely simple setup with minimal technical knowledge required
  • + Writers own their subscriber list and can export at any time
  • + Built-in discovery through Substack network and recommendations

Cons

  • - Limited customization and branding options compared to dedicated email tools
  • - 10% platform fee can become expensive as revenue scales
  • - Basic email design and layout capabilities with fewer templates