Overview

Postmark and Mailgun represent two different approaches to transactional email. Postmark has built its reputation on being the fastest, most reliable transactional email service by focusing exclusively on that use case. Mailgun offers a broader platform with additional features for optimization and validation.

Both are trusted by developers worldwide and offer robust APIs, but they serve different needs and priorities.

Deliverability Comparison

Postmark's key differentiator is their transactional-only infrastructure. By refusing to send marketing emails, they maintain pristine IP reputation and achieve consistently high deliverability. Their emails typically arrive in seconds, not minutes.

Mailgun achieves good deliverability but handles both transactional and marketing email on the same infrastructure. This shared approach can occasionally impact delivery times and inbox placement during high marketing volume periods.

Developer Experience

Both platforms offer excellent developer experiences with comprehensive APIs, multiple SDKs, and webhook support. Mailgun provides slightly more SDK options and additional features like email validation API. Postmark's API is clean and focused, with MailMason providing a solid templating system.

For inbound email processing, both platforms offer parsing capabilities, though Mailgun's is more feature-rich with routing rules and storage options.

Pricing Analysis

At 100,000 emails per month, Mailgun costs $75 compared to Postmark's $115 - a 35% savings. This gap increases at higher volumes. However, Postmark's longer message retention (45 days vs 5-7 days) and dedicated infrastructure may justify the premium for some teams.

Consider the total cost of ownership, including time spent on deliverability issues. Postmark's focus on reliability may reduce debugging time and support burden.

When Each Tool Shines

Choose Postmark when: You need the fastest possible delivery for password resets, two-factor auth codes, or order confirmations. Their transactional-only focus ensures your critical emails arrive instantly.

Choose Mailgun when: You want a comprehensive email platform with validation, optimization, and both transactional and marketing capabilities at a lower price point.

The Sequenzy Alternative

For SaaS companies, the real question might be whether you need separate transactional and marketing email providers at all. Sequenzy unifies both in a single platform with Stripe integration, behavioral automation, and simpler pricing.

Instead of paying per email and managing multiple providers, Sequenzy offers a flat monthly rate based on subscribers - making it easier to budget and scale your email operations.