Best Email APIs

Best overall: Mailgun

████████▒░ 84 / 100 data score

Mailgun is an email delivery platform aimed at developers, covering transactional and bulk sending, deliverability, email validation, and inbound processing. The REST API supports basic and API-key auth, webhooks, six SDKs, and an official MCP server, with US and EU regions. Pricing is published and self-serve: 100 emails/day free, paid plans from $15/month. It carries SOC 2 Type 2, HIPAA, GDPR, ISO 27001, PCI DSS, and an SLA. Used by Microsoft, Wikipedia, and American Express.

From $15 month · free tier available.

How it stacks up

• ✓ Mailjet starts lower at $9 per month vs $15 for Mailgun.
• ✓ Mailgun offers a free tier while Amazon Simple Email Service does not, so Mailgun is easier to trial before committing.
• ✓ Brevo starts lower at $9 per month vs $15 for Mailgun.

Best for: Prototypes and side projects - free to start, no sales call; Regulated or enterprise workloads - compliance attestations and an enterprise plan; AI agents and automation - an agent-ready surface (MCP / llms.txt).

Mailgun profile → · Mailgun vs Mailjet →

At a glance

Quick pick by use case

If you only have thirty seconds, find your situation:

• If you want the strongest all-round pick, pick Mailgun - our default pick: strongest across pricing, trust and breadth.
• If you want to start free, pick Mailgun - free tier: $0/mo Free plan: 100 emails per day, 1 custom sending domain, ticket support, RESTful ema….
• If you're buying for a regulated or large team, pick Mailgun - for regulated or large teams: SOC 2 Type II, HIPAA, published SLA.
• If you want the lowest published entry price, pick MailerSend - from $7 month to start; compare on your real usage, not the entry price.
• If you're wiring this into coding agents or AI workflows, pick Mailgun - easiest to wire up programmatically: MCP server.
• If you want the broadest documented surface, pick Amazon Simple Email Service - 168 documented actions; breadth isn't quality, but it's the most to build on.

The picks in depth

• #1 Mailgun

  ████████▒░ 84 / 100
  • Best overall
  • Best free pick
  • Best for enterprise
  • Best for agents

  Mailgun is an email delivery platform aimed at developers, covering transactional and bulk sending, deliverability, email validation, and inbound processing. The REST API supports basic and API-key auth, webhooks, six SDKs, and an official MCP server, with US and EU regions. Pricing is published and self-serve: 100 emails/day free, paid plans from $15/month. It carries SOC 2 Type 2, HIPAA, GDPR, ISO 27001, PCI DSS, and an SLA. Used by Microsoft, Wikipedia, and American Express.

  PricingHybrid · from $15 month · free tier ✓

  TrustSOC 2 Type II · HIPAA · GDPR · ISO 27001 · PCI DSS

  Does

  • Transactional send
  • Inbound parsing
  • Templates
  • Batch send
  • Scheduled send
  • SMTP relay
  • Dedicated IP
  • Email validation
  • Analytics

  Used byMicrosoft, Wikipedia, American Express, Lyft

  Strengthstransparent public pricing · a free tier · self-serve signup

  ScoresAgent 60 · Pricing 100 · Setup 100 · Docs 45 · Procurement 100 · Trust 100

  Mailgun profile →

• #2 Mailjet

  ████████▒░ 84 / 100

  Mailjet is an email platform for transactional and marketing email, built for developers and marketers, with EU data residency in Frankfurt and Belgium. The REST API uses basic auth, webhooks, seven SDKs, and an official MCP server. Pricing is published and self-serve: 6,000 emails/month free, paid plans from $9/month. It holds SOC 2 Type 2, HIPAA, GDPR, ISO 27001, PCI DSS, and a published SLA.

  PricingHybrid · from $9 month · free tier ✓

  TrustSOC 2 Type II · HIPAA · GDPR · ISO 27001 · PCI DSS

  Does

  • Transactional send
  • Marketing / broadcasts
  • Inbound parsing
  • Templates
  • Batch send
  • Scheduled send
  • SMTP relay
  • Dedicated IP
  • Analytics

  Strengthstransparent public pricing · a free tier · self-serve signup

  ScoresAgent 60 · Pricing 100 · Setup 100 · Docs 45 · Procurement 100 · Trust 100

  Mailjet profile →

• #3 Amazon Simple Email Service

  ██████▓░░░ 68 / 100
  • Broadest surface

  Amazon SES is AWS's cloud email service for high-volume transactional, marketing, and inbound email. Pricing is pay-per-use at $0.10 per 1,000 emails, with 3,000/month free for the first year, and signup is self-serve through AWS. The REST API uses signature auth and webhooks, with seven SDKs and an official MCP server, and it carries SOC 2 Type 2, HIPAA, GDPR, ISO 27001, PCI DSS, and an SLA. Used by Netflix, Duolingo, and Grab.

  PricingUsage · from $0.10 1,000 emails · free tier ✗

  TrustSOC 2 Type II · HIPAA · GDPR · ISO 27001 · PCI DSS

  Does

  • Transactional send
  • Inbound parsing
  • Templates
  • Batch send
  • SMTP relay
  • Dedicated IP
  • Analytics

  Used byNetflix, Duolingo, Grab, BCAA

  Strengthstransparent public pricing · self-serve signup · SOC 2 Type II

  The catchCheapest at scale, but bare-bones: new accounts start sandboxed, and deliverability and IP warmup are your job.

  ScoresAgent 55 · Pricing 85 · Setup 60 · Docs 25 · Procurement 85 · Trust 100

  Amazon Simple Email Service profile →

• #4 Brevo

  ████████▒░ 86 / 100

  Brevo is an all-in-one customer engagement platform spanning transactional and marketing email, SMS, WhatsApp, automation, and CRM. The REST API supports API-key and OAuth2 auth, webhooks, seven SDKs, and an official MCP server. Pricing is published and self-serve with a free tier of 300 emails/day and paid plans from $9/month, and the platform is GDPR and ISO 27001 compliant with a published SLA. Used by eBay, H&M, and Louis Vuitton.

  PricingHybrid · from $9 month · free tier ✓

  TrustGDPR · ISO 27001

  Does

  • Transactional send
  • Marketing / broadcasts
  • Inbound parsing
  • Templates
  • Batch send
  • Scheduled send
  • SMTP relay
  • Dedicated IP
  • Analytics

  Used byeBay, H&M, Louis Vuitton, Sodexo

  Strengthstransparent public pricing · a free tier · self-serve signup

  Avoid ifYou have strict compliance requirements

  ScoresAgent 90 · Pricing 100 · Setup 100 · Docs 75 · Procurement 100 · Trust 50

  Brevo profile →

• #5 SendGrid

  ██████▓░░░ 67 / 100

  SendGrid, part of Twilio, is a high-scale email platform for transactional and marketing email, with proven deliverability and domain authentication. The REST API supports API-key and basic auth, webhooks, seven SDKs, and an official MCP server, with global and EU regions. Pricing is published and self-serve from about $20/month. It carries SOC 2 Type 2, GDPR, ISO 27001, PCI DSS, and a published SLA. Used by Shopify.

  PricingHybrid · from $19.95 month · free tier ✗

  TrustSOC 2 Type II · GDPR · ISO 27001 · PCI DSS

  Does

  • Transactional send
  • Marketing / broadcasts
  • Inbound parsing
  • Templates
  • Batch send
  • Scheduled send
  • SMTP relay
  • Dedicated IP
  • Email validation
  • Analytics

  Used byShopify

  Strengthstransparent public pricing · self-serve signup · SOC 2 Type II

  Avoid ifYou want to try it free before paying

  ScoresAgent 40 · Pricing 85 · Setup 60 · Docs 45 · Procurement 85 · Trust 85

  SendGrid profile →

• #6 MailerSend

  ███████░░░ 71 / 100
  • Cheapest to start

  MailerSend is a transactional email platform built for developers but accessible to non-technical teams, also covering SMS, inbound routing, and email verification. The REST API uses API-key auth, webhooks, six SDKs, and an official MCP server. Pricing is published and self-serve with 500 emails/month free and paid plans from $7/month. It is GDPR and ISO 27001 compliant with a published SLA.

  PricingHybrid · from $7 month · free tier ✓

  TrustGDPR · ISO 27001

  Does

  • Transactional send
  • Inbound parsing
  • Templates
  • Batch send
  • Scheduled send
  • SMTP relay
  • Dedicated IP
  • Email validation
  • Analytics

  Strengthstransparent public pricing · a free tier · self-serve signup

  Avoid ifYou have strict compliance requirements

  ScoresAgent 65 · Pricing 100 · Setup 85 · Docs 25 · Procurement 100 · Trust 50

  MailerSend profile →

• #7 Postmark

  ██████▒░░░ 65 / 100

  Postmark is a transactional email service focused on fast, reliable delivery for notifications, password resets, and receipts. The REST API uses API-key auth, webhooks, seven SDKs, and an official MCP server. Pricing is published and self-serve: 100 emails/month free, paid plans from $15/month. It is GDPR compliant. Used by Asana, IKEA, and UNICEF.

  PricingHybrid · from $15 month · free tier ✓

  TrustGDPR

  Does

  • Transactional send
  • Marketing / broadcasts
  • Inbound parsing
  • Templates
  • Batch send
  • SMTP relay
  • Dedicated IP
  • Analytics

  Used byLiveChat, Asana, IKEA, UNICEF

  Strengthstransparent public pricing · a free tier · self-serve signup

  Avoid ifYou have strict compliance requirements

  ScoresAgent 60 · Pricing 100 · Setup 100 · Docs 15 · Procurement 100 · Trust 15

  Postmark profile →

• #8 Resend

  ████████░░ 82 / 100

  Resend is a developer-first REST email API for transactional, marketing, and inbound mail. It ships API-key auth, webhooks, idempotency keys, six SDKs, and an official MCP server, with multi-region sending across the US, EU, Brazil, and Japan. Pricing is published and self-serve, with a free tier of 3,000 emails/month and paid plans from $20. It carries SOC 2 Type 2, GDPR, and a published SLA. Used by Warner Bros, Gumroad, and Replit.

  PricingHybrid · from $20 1,000 emails · free tier ✓

  TrustSOC 2 Type II · GDPR

  Does

  • Transactional send
  • Marketing / broadcasts
  • Inbound parsing
  • Templates
  • Batch send
  • Scheduled send
  • SMTP relay
  • Dedicated IP
  • Analytics

  Used byWarner Bros, Gumroad, Tailwind, Replit

  Strengthstransparent public pricing · a free tier · self-serve signup

  ScoresAgent 70 · Pricing 100 · Setup 85 · Docs 75 · Procurement 100 · Trust 60

  Resend profile →

See all 11 Email APIs compared →

How we rank

The headline score is the average of six 0-100 axes computed only from each API’s published, sourced fields: agent-friendliness, pricing transparency, setup speed, docs quality, procurement ease, and trust readiness. An unknown signal scores 0 for its axis - we credit what’s confirmed, never guess. The score is one input, not the verdict: we lead with each pick’s trade-off, and where a job has only one real option we say so rather than crown it. Full method on the methodology page.

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• ✓ Every field cited. Each profile links the source for every claim - check us.
• ✓ Public audit log. Every change to this data is recorded per field, with who changed it and why.
• ✓ Published, deterministic methodology. The score is a formula over the same fields you can see - recompute it yourself.
• ✓ Zero affiliate links, zero ads, zero paid placement. Money never moves rank.
• ✓ No reviews yet - and we say so rather than synthesizing them.

Frequently asked questions