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Mailgun vs SendGrid

Live comparisonView as JSON
Mailgun
cloudFree trial (100 emails/day)
SendGrid
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)$19.95/mo Essentials$89.95/mo ProCustom Premier
Open Source
Self-Hosted
SDK Languages
pythonjavascriptgojavarubycsharpphp
pythonjavascriptgojavarubycsharpphp
Frameworks
None listed
None listed
Compliance
soc2gdpr
soc2hipaagdpr
Best For
Email API with strong inbound email parsing — useful for agents that need to receive and process emails, not just send
High-volume transactional and marketing email with proven deliverability — the established default
Limitations
Free tier is limited to a trial period; UI is less polished than competitors; owned by Sinch, product direction less predictable
UI and developer experience feel dated compared to Resend; owned by Twilio, so pricing and product direction tied to Twilio strategy; support quality inconsistent on lower tiers

Supported Not supported Unverified

SendGrid and Mailgun both offer mature email APIs with REST and SMTP delivery. Mailgun ships an official MCP server. SendGrid does not. Mailgun also provides more expressive inbound routing. SendGrid wins on per-endpoint credential scoping.

Where Mailgun wins

  • MCP server for agent tool calls. Mailgun ships an official MCP server. SendGrid has no documented MCP server. MCP agents can invoke Mailgun operations as tool calls without building an adapter. Integrating SendGrid requires writing a custom adapter.

  • Inbound Routes with filter expressions. Mailgun Routes filter inbound email at the provider before routing to an agent endpoint. Filter expressions like match_recipient("support\\+(.*)@yourdomain.com") route only matching messages to the configured URL or S3 store. The agent receives pre-filtered messages instead of every incoming email on the domain. SendGrid's Inbound Parse Webhook delivers structured JSON for all incoming email on a configured MX domain. Routing happens in the consumer. Agents must read every message and apply routing logic themselves.

  • Domain Sending Keys for minimal-privilege credentials. Mailgun Domain Sending Keys are per-domain, send-only credentials that cannot access logs, routes, suppressions, or account management. This is a named, first-class credential type for send-only access. Resend and Postmark have comparable constructs. SendGrid's minimum send-scoped key can narrow to "Mail Send" only but draws from the same key type as broader administrative keys.

Where SendGrid wins

  • Per-endpoint API key scoping. SendGrid custom API keys restrict to specific endpoints. A key can scope to "Mail Send" with read-only "Suppressions" access. Agents monitoring bounces can send and read lists with one key that cannot create templates or modify contact lists. Mailgun offers Domain Sending Keys (send-only, per-domain) and standard API keys with role-based access. It does not offer the same per-endpoint mix-and-match capability.

  • Marketing Campaigns and list management. SendGrid includes Marketing Campaigns with contact list management, segmentation, and single sends via API. Agents managing subscriber lists can operate both surfaces through a single provider. Mailgun focuses on transactional and bulk sending. Its contact list and marketing capabilities are less mature.

The agentic difference

Mailgun's MCP server is the decisive advantage. Agents can invoke email operations as tool calls without building an adapter. Mailgun's inbound Routes provide filter-at-source routing that reduces agent-side processing. Only relevant messages are delivered to the handler. SendGrid requires custom MCP integration and handles all inbound routing inside consumer code.

SendGrid's per-endpoint API key model is more nuanced than Mailgun's. An agent can cover send plus suppression-read without covering template management. This matters for agents monitoring deliverability. For agents managing marketing lists, SendGrid covers both surfaces in one provider. Neither removes the need to build a custom MCP adapter for SendGrid.

When to pick which

  • Pick Mailgun when MCP tool-call surface is required without custom implementation. Pick Mailgun when inbound email routing with filter expressions reduces agent-side routing logic.

  • Pick SendGrid when per-endpoint API key scoping with read-only suppression access is required. Pick SendGrid when the agent also manages marketing contact lists and you can build MCP integration custom.

Last verified: 2026-05-09