Compare Tools

Mailgun vs Resend

Live comparisonView as JSON
Mailgun
cloudFree trial (100 emails/day)
Resend
cloudFree (100 emails/day)
Transactional
Marketing
Inbound Parsing
Template Engine
Deliverability Tools
Pricing
Free trial (100 emails/day)$35/mo Foundation$90/mo ScaleCustom Enterprise
Free (100 emails/day)$20/mo ProCustom Enterprise
Open Source
Self-Hosted
SDK Languages
pythonjavascriptgojavarubycsharpphp
pythonjavascripttypescriptgorubyjavaphpelixir
Frameworks
None listed
None listed
Compliance
soc2gdpr
soc2gdpr
Best For
Email API with strong inbound email parsing — useful for agents that need to receive and process emails, not just send
Modern developer experience for transactional email — clean API, React Email support, great docs
Limitations
Free tier is limited to a trial period; UI is less polished than competitors; owned by Sinch, product direction less predictable
Newer platform with smaller track record; no marketing email features; deliverability reputation still building compared to SendGrid

Supported Not supported Unverified

Resend and Mailgun both ship official MCP servers and both support inbound email. Resend wins on webhook reliability. Mailgun wins on inbound routing and minimal-privilege credentials.

Where Resend wins

  • Svix webhook infrastructure with idempotency-key headers. Resend delivers webhook events via Svix with idempotency-key headers on every delivery. It retries 6 times with exponential backoff and includes HMAC-SHA256 signature verification. Mailgun webhooks support HMAC signing and retry on delivery failure, but do not include idempotency-key headers. Agent pipelines processing bounces or complaints need idempotency to avoid double-processing.

Where Mailgun wins

  • Inbound Routes with filter expressions. Mailgun Routes filter inbound email at the provider before routing to an agent endpoint. Filter expressions like match_recipient("agent\\+(.*)@yourdomain.com") extract routing parameters from the To address and forward only matching messages. Agents receive pre-filtered messages instead of every incoming email. Resend has no documented inbound email processing.

  • Domain Sending Keys for minimal-privilege credentials. Mailgun Domain Sending Keys are per-domain, send-only credentials. A key can only send from a specific domain. It cannot read logs, modify Routes, access suppressions, or perform account management. Resend offers "Sending Access" keys with optional domain restriction, which is comparable. Mailgun's Domain Sending Keys are a named, first-class construct.

The agentic difference

Both tools are MCP-ready. Resend's Svix-backed webhooks provide idempotency-key deduplication that Mailgun lacks. For agent pipelines processing bounces or complaints, this guarantee matters.

Mailgun's inbound Routes solve a real problem for agents receiving email. Pre-delivery filtering means only relevant messages reach the agent endpoint. Filter expressions extract routing state embedded in the To address. Mailgun's Domain Sending Keys offer a cleaner minimal-privilege story for send-only agents. Neither of these closes the gap on webhook delivery guarantees.

When to pick which

  • Pick Resend when outbound webhook reliability with idempotency-key deduplication matters, or when the agent does not need inbound email processing.

  • Pick Mailgun when inbound email routing with filter expressions is required. Routes reduce agent-side routing logic. Pick Mailgun when you need Domain Sending Keys as an explicit per-domain send-only credential.

Last verified: 2026-05-09