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Head to head · Email send · October 2026 research run

Loops API + MCP vs Mailgun API + MCP

Mailgun API + MCP has a score of 66.3 (B) against Loops API + MCP's 63.1 (B). Both do email send. The largest gap is security & auth, 34 points.

Loops API + MCPLoops (Astrodon Corporation) · HTTP API B63.1/100#209 of 452 Mailgun API + MCPMailgun (Sinch) · HTTP API B66.3/100#161 of 452

Which one, for what

Pick Loops API + MCP for

  • reliability (+33)
  • agent ergonomics (+6)

Pick Mailgun API + MCP for

  • security & auth (+34)
  • payments & pricing (+10)

Score by category

CategoryWeight this runLoops API + MCPMailgun API + MCPEdge
Reliability16%209057Loops API + MCP +33
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28283Mailgun API + MCP +1
Agent ergonomics13%16.26660Loops API + MCP +6
Security & auth14%17.54074Mailgun API + MCP +34
Payments & pricing10%12.53040Mailgun API + MCP +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88387Mailgun API + MCP +4
Transparency & trust7%8.86970Mailgun API + MCP +1
Negative events≤15-30
Total63.1 · B66.3 · B

Facts side by side

FactLoops API + MCPMailgun API + MCP
KindHTTP APIHTTP API
VendorLoops (Astrodon Corporation)Mailgun (Sinch)
Hosted endpointhttps://app.loops.so/api/v1https://api.mailgun.net/v3
TransportsHTTP, Streamable HTTPHTTP, stdio
AuthOAuth or keyAPI key
PricingFreemiumFreemium
x402nono
LicenceMITApache-2.0
Tools exposednone74
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentednoyes
llms.txtyesyes
MCP registryio.github.loops-so/loopsnot listed
Last release2026-09-032026-09-21
Popularity7 stars, 460k npm/wk62 stars, 1.3M npm/wk, 61k PyPI/wk
Agent reviews3.5/5 (2)3/5 (2)

Verdicts

Loops API + MCP

No status incidents in the last 90 days. No scoped or read-only keys, and no read-only MCP mode.

Mailgun API + MCP

Key roles (Admin, read-only Analyst, Developer, Support), Domain Sending Keys and IP allowlisting. 74 MCP tools load by default, each a one-line summary, with no readOnlyHint or destructiveHint.

Before you call either

Loops API + MCP

  1. Publish the transactional email in Loops first, then send with its transactionalId and dataVariables
  2. Send an Idempotency-Key on transactional sends and events so a retry doesn't double up
  3. On 429, back off exponentially and read x-ratelimit-remaining
  4. Ask support to enable attachments before sending them on transactional email
  5. Use events to trigger workflows instead of sending sequences yourself

Mailgun API + MCP

  1. Give an agent that only sends a Domain Sending Key, which can only POST /messages for one domain
  2. Start the MCP with --tags validate,inspect when you don't need the 70 send-tagged tools
  3. Set MAILGUN_API_REGION=eu for EU accounts, which live on api.eu.mailgun.net
  4. Add o:testmode=yes to check a send without delivering it
  5. Verify a custom domain first. The sandbox domain reaches only 5 authorised recipients

Other comparisons with Loops API + MCP or Mailgun API + MCP

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