Amazon SES vs Mailgun: Which Transactional Email API Wins?

Amazon SES and Mailgun are both popular choices for transactional email, but they solve the problem differently. SES is raw email infrastructure priced at $0.10 per 1,000 emails with no monthly minimums. Mailgun is a developer-friendly email API starting at $15/month with better tooling out of the box. The right choice depends on whether you want the cheapest possible sending or a more complete developer platform.

If you are already on AWS and your team can handle DNS configuration, IAM policies, and bounce handling without hand-holding, SES will save you significant money at any volume. If you want a faster setup, better debugging tools, and built-in email validation without touching AWS, Mailgun gets you sending sooner with less operational overhead.

Pricing Comparison

Pricing is the biggest differentiator between these two services, and it is not close at scale.

Amazon SES Pricing

SES charges a flat $0.10 per 1,000 emails with no monthly base fee. If your application runs on EC2, you get 62,000 emails per month free as part of the AWS Free Tier. There are no plans or tiers to navigate. You pay for what you send, plus optional add-ons like dedicated IPs ($24.95/month each) and a Virtual Deliverability Manager ($0.07 per 100 emails for insights).

At 100,000 emails per month, SES costs about $10. At 1 million emails, about $100. At 10 million, about $1,000. The math is simple and predictable.

For more details, see our Amazon SES pricing breakdown.

Mailgun Pricing

Mailgun’s pricing is tier-based. After a free trial period (5,000 emails/month for 3 months), the Foundation plan starts at $35/month for 50,000 emails. The Scale plan at $90/month adds dedicated IPs, email validation, and longer log retention. Custom pricing is available for high-volume senders.

At 100,000 emails per month, Mailgun costs roughly $90 on the Scale plan. At 1 million emails, you are looking at custom pricing that typically comes in around $400-600/month depending on negotiation. Check our Mailgun pricing breakdown for specifics.

Cost Per Email at Scale

Volume	Amazon SES	Mailgun
10,000/mo	$1	$35 (Foundation)
100,000/mo	$10	$90 (Scale)
500,000/mo	$50	~$300 (Custom)
1,000,000/mo	$100	~$500 (Custom)

SES wins on raw cost at every volume. But cost is not the only variable. The operational overhead of managing SES yourself may eat into those savings.

API Design and Developer Experience

Amazon SES API

SES provides a RESTful API (v2) and an SMTP interface. The API handles sending, template management, configuration sets, and account-level settings. You authenticate via AWS IAM credentials, which means your email sending is tied into the broader AWS permission model.

Key characteristics:

• AWS SDK integration in every major language (Python boto3, Node.js aws-sdk, Java, Go, etc.)
• IAM-based authentication with fine-grained permission policies
• Configuration sets for organizing sending behavior and event publishing
• SES v2 API with consolidated endpoints for sending, templates, and account management
• SNS integration for delivery notifications (bounces, complaints, delivery confirmations)
• No built-in email validation — you need a third-party service or your own solution

The developer experience is functional but not friendly. Setting up SES involves domain verification via DNS, requesting production access (you start in sandbox mode with limited sending), configuring SNS topics for bounce handling, and managing IAM policies. None of this is difficult for experienced AWS engineers, but it adds hours of setup time compared to Mailgun’s “sign up and send” flow.

Mailgun API

Mailgun’s API is designed specifically for email. Endpoints are clean and domain-scoped. You authenticate with a simple API key rather than navigating IAM. The API covers sending, receiving, validation, routing, and event querying.

Key characteristics:

• Simple API key authentication — no IAM policies needed
• RESTful endpoints scoped to your sending domain
• Built-in email validation API for checking addresses before sending
• Powerful inbound routing with pattern matching on recipients, headers, and content
• Events API for querying delivery, open, click, and bounce events with filters
• SDKs for Python, Ruby, Java, Go, PHP, C#, and Node.js
• Log retention with searchable message history (duration varies by plan)

Mailgun gets you from zero to sending in about 15 minutes. Domain verification is straightforward, the API key works immediately, and the dashboard shows delivery events in real time. For teams that want to move fast without managing infrastructure, this is the key advantage.

Deliverability

Both services deliver transactional email reliably, but the mechanisms differ.

Amazon SES Deliverability

SES handles deliverability through configuration sets, suppression lists, and the optional Virtual Deliverability Manager (VDM). SES automatically manages bounce and complaint suppression at the account level, which protects your sender reputation. VDM adds inbox placement insights and engagement tracking for an additional per-email fee.

SES starts you in sandbox mode with restricted sending until you request production access. This is a quality gate — it forces you to demonstrate proper email practices before sending at volume. Once approved, SES provides shared IPs by default. Dedicated IPs are available at $24.95/month each.

The trade-off is that SES gives you less visibility into deliverability without VDM. You get bounce and complaint notifications via SNS, but there is no built-in dashboard showing inbox placement rates or provider-specific performance. You need to build that monitoring yourself or pay for VDM.

Mailgun Deliverability

Mailgun provides real-time delivery dashboards, automated bounce processing, feedback loop integration, and dedicated IPs on the Scale plan ($59/month as an add-on on Foundation). The built-in email validation API is a deliverability asset — checking addresses before sending reduces bounces, which protects sender reputation.

Mailgun’s infrastructure handles billions of emails monthly. Their deliverability team manages IP reputation across shared and dedicated pools. The Scale plan includes inbox placement testing, which gives you data on where your emails land across Gmail, Outlook, and Yahoo.

For transactional email, both services deliver well. The difference is observability: Mailgun shows you what is happening out of the box. SES requires more setup to get the same visibility.

When to Pick Amazon SES

SES is the right choice if:

• Your team already works in AWS. If you manage EC2, Lambda, RDS, and other AWS services daily, adding SES is natural. The IAM integration, CloudWatch metrics, and SNS event handling fit into your existing workflows.
• You send high volume and cost matters. At 1 million emails per month, SES saves $400-500 versus Mailgun. At 10 million, the savings are thousands per month. For cost-sensitive operations, no competitor matches SES on price.
• You have engineering resources for email operations. SES requires you to manage bounce handling, complaint processing, suppression lists, and deliverability monitoring. If your team can handle this, the savings are worth it.
• You need transactional email integrated with other AWS services. Triggering emails from Lambda functions, SQS queues, or Step Functions is straightforward with SES as part of the same ecosystem.

SES is not the right choice if your team lacks AWS experience, if you need email validation built in, or if you want a polished dashboard without building one yourself.

When to Pick Mailgun

Mailgun is the better choice if:

• You want to start sending fast. Sign up, verify your domain, and send your first email in 15 minutes. No sandbox restrictions, no IAM setup, no SNS configuration.
• You need built-in email validation. Mailgun’s validation API checks addresses for deliverability, disposability, and syntax errors before you send. This saves bounces and protects sender reputation. SES has no equivalent.
• You process inbound email. If your application receives and routes emails (helpdesk, CRM, automated workflows), Mailgun’s inbound routing with pattern matching is significantly more capable than SES’s basic receiving setup.
• You want deliverability insights without extra configuration. Real-time dashboards, event logs, and inbox placement data come included. No need to wire up SNS, CloudWatch, and custom monitoring.
• Your team is not on AWS. If your infrastructure runs on GCP, Azure, Heroku, or bare metal, Mailgun is platform-agnostic. SES only makes sense within the AWS ecosystem.

Mailgun is harder to justify if you send millions of emails monthly and cost is the primary concern, or if your team already has deep AWS expertise.

What About Postmark and SendGrid?

If neither SES nor Mailgun feels like the right fit, two other transactional email services are worth evaluating.

Postmark is purpose-built for transactional email with industry-leading deliverability — 98.7% inbox placement in third-party tests. It does not allow marketing email at all, which means its entire infrastructure is optimized for speed and reliability. Pricing starts at $15/month for 10,000 emails. If inbox placement for password resets, receipts, and notifications is your top priority, Postmark is hard to beat.

SendGrid handles both transactional and marketing email on one platform. It offers a free tier of 100 emails/day and has 320+ native integrations. The trade-off is slower customer support and shared IP reputation issues on lower tiers. See our SendGrid vs Mailgun comparison for a detailed breakdown.

For the full picture, read our best transactional email services roundup.

Our Verdict

For most teams, the decision comes down to a clear question: do you have AWS expertise and want the lowest cost, or do you want a better developer experience and faster setup?

Pick Amazon SES if you are already on AWS, send at high volume, and have engineers who can manage email infrastructure. The $0.10/1,000 pricing is unmatched.

Pick Mailgun if you want to get sending quickly, need email validation, or process inbound email. The higher price buys you a more complete platform with less operational work.

If transactional deliverability matters more than anything else, look at Postmark. If you need transactional plus marketing in one platform, look at SendGrid.

Sources

1. Amazon SES Pricing — accessed 2026-04-13
2. Mailgun Pricing — accessed 2026-04-13
3. Amazon SES Developer Guide — accessed 2026-04-13
4. Mailgun API Documentation — accessed 2026-04-13
5. Postmark Deliverability Report — accessed 2026-04-13