Two transactional email providers, compared on price, features and ratings, so you can pick fast.
Updated November 2026
THE VERDICT
Customer.io wins on editor tools and support. Mailgun wins on price and developer experience.
Customer.io and Mailgun take different pricing approaches. Mailgun rates higher with developers (4.5 vs 4.4 on G2). Pick based on volume and team, and the scorecard below breaks down where each one leads.
Winner cells are tinted, green where Customer.io leads, violet where Mailgun does.
FAQ
Mailgun rates higher on G2 (4.5 vs 4.4). Ratings are aggregated from public review platforms as of the date shown.
Customer.io's entry-level Essentials plan starts at $100 per month and includes 5,000 profiles and 1 million emails per month. Billing is based on the maximum number of uniquely identified profiles in the account during the month, with overage charges of roughly $0.009 per additional profile and $0.12 per 1,000 emails beyond plan limits. The Premium plan starts around $1,000 per month on an annual contract and adds managed deliverability, dedicated IPs, and HIPAA compliance with a signed BAA, while Enterprise pricing is custom.
Mailgun provides official SDKs for Python, Ruby, PHP, Java, Node.js, and Go. Because it also exposes a standard REST API and SMTP relay, it can be integrated from virtually any language or framework, including C# and .NET, even without an official SDK.
Yes. Many teams route different message types through different providers or fail over between them. Courier lets you send through both behind a single API and switch providers without changing your code.
Why not both?
Use both behind one API.
Route Customer.io, Mailgun, or both, and switch providers without changing your code. Courier sits in front of every channel.
Pricing, plans and feature availability as of November 2026 and may change. Ratings are aggregated from public review platforms. Mailgun is a Sinch product.