SendGrid vs Mailgun: Enterprise Email Infrastructure Compared

Overview

SendGrid (now part of Twilio) and Mailgun (part of Sinch) are both established email infrastructure providers trusted by thousands of companies at scale. They've been competing for over a decade, and both are solid choices.

The differences are nuanced - this comparison will help you understand which aligns better with your specific needs.

Key Differences

Marketing vs Infrastructure Focus

SendGrid tries to be both email infrastructure and marketing platform. Their Marketing Campaigns product includes contact management, automation, and campaign tools. It's a Jack-of-all-trades approach - decent at both, exceptional at neither.

Mailgun stays focused on infrastructure. It's primarily an email delivery API with analytics. If you need marketing automation, you'll pair Mailgun with another tool. This focus means Mailgun tends to be more reliable for pure transactional use cases.

Developer Experience

Mailgun has the edge here. The API design is cleaner, documentation is more developer-friendly, and the overall experience feels more coherent. They also offer more granular control over sending behavior.

SendGrid has a capable API but the interface feels more fragmented, especially since marketing and transactional are somewhat separate products. The documentation is comprehensive but can be overwhelming.

Reliability and Uptime

Both are reliable at scale, but Mailgun commits to a 99.99% uptime SLA versus SendGrid's 99.95%. In practice, both have occasional incidents, but Mailgun's commitment is stronger on paper.

SendGrid handles massive volume for companies like Airbnb and Uber, so they're certainly capable. The Twilio acquisition brought additional infrastructure resources.

Pricing Comparison

SendGrid's pricing is more aggressive at lower volumes. Mailgun's pricing is more transparent at high volumes. Both offer custom enterprise pricing.

Pros and Cons

Who Should Choose What

Choose SendGrid if:

• You want both transactional and marketing in one platform
• You're using other Twilio products (SMS, voice)
• You're at lower volume and price-sensitive
• You need enterprise contracts and compliance
• You value having a permanent free tier

Choose Mailgun if:

• You prioritize developer experience
• You need the highest uptime guarantees
• You're focused on transactional email only
• You want granular control over email behavior
• You're at high volume and want transparent pricing

The Bottom Line

Both SendGrid and Mailgun are battle-tested infrastructure providers. You won't go wrong with either for basic transactional email needs.

The key differentiator is focus. SendGrid tries to be a complete email platform (transactional + marketing). Mailgun focuses on being the best email delivery infrastructure.

If you need marketing features and want one platform, SendGrid makes sense. If you want the most reliable, developer-friendly transactional infrastructure and will use a separate marketing tool, Mailgun is the better choice.

For most SaaS founders, the honest recommendation is to consider newer alternatives like Resend or Postmark for transactional email - they offer better developer experience with comparable reliability. SendGrid and Mailgun are best for teams with specific requirements around scale, compliance, or ecosystem integration.