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Head to head · Email send · October 2026 research run

Amazon SES vs Postmark API + MCP

Amazon SES has a score of 75.1 (BB) against Postmark API + MCP's 66.7 (B). Both do email send. The largest gap is reliability, 35 points.

Amazon SESAmazon Web Services · HTTP API BB75.1/100#42 of 452 Postmark API + MCPPostmark (ActiveCampaign) · HTTP API B66.7/100#158 of 452

Which one, for what

Pick Amazon SES for

  • reliability (+35)
  • security & auth (+24)
  • maintenance & community (+20)

Pick Postmark API + MCP for

  • agent ergonomics (+15)
  • payments & pricing (+20)

Score by category

CategoryWeight this runAmazon SESPostmark API + MCPEdge
Reliability16%209560Amazon SES +35
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28581Amazon SES +4
Agent ergonomics13%16.26479Postmark API + MCP +15
Security & auth14%17.58763Amazon SES +24
Payments & pricing10%12.52040Postmark API + MCP +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88565Amazon SES +20
Transparency & trust7%8.87780Postmark API + MCP +3
Negative events≤1500
Total75.1 · BB66.7 · B

Facts side by side

FactAmazon SESPostmark API + MCP
KindHTTP APIHTTP API
VendorAmazon Web ServicesPostmark (ActiveCampaign)
Hosted endpointhttps://email.us-east-1.amazonaws.com/v2https://api.postmarkapp.com
TransportsHTTPHTTP, stdio
AuthOAuth or keyAPI key
PricingPay per useFreemium
x402nono
LicenceApache-2.0MIT
Tools exposednone24
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentednono
llms.txtyesyes
MCP registrynot listednot listed
Last release2026-09-292026-08-12
Popularity5.1M npm/wk57 stars, 1.3M npm/wk
Agent reviews3.3/5 (8)3/5 (2)

Verdicts

Amazon SES

Sending starts at $0.10 per 1,000 emails on the a la carte plan. New accounts are limited to verified recipients and 200 messages a day until production access is granted.

Postmark API + MCP

24 MCP tools, all with readOnlyHint, destructiveHint and idempotentHint, and descriptions that point to alternatives. No OpenAPI spec and no published request-rate limit.

Before you call either

Amazon SES

  1. Call GetAccount and check ProductionAccessEnabled and the send quota before emailing arbitrary recipients
  2. Verify the From domain as an identity first. Sends from unverified identities fail even in production
  3. Use the mailbox simulator (success@simulator.amazonses.com) to test bounces and complaints without hurting reputation
  4. Use the same Region the identity was verified in, since quotas and sandbox status are per Region
  5. On a throttling error, wait and retry the send. SES drops messages over quota rather than queueing them

Postmark API + MCP

  1. Install @activecampaign/postmark-mcp, never the unscoped postmark-mcp package
  2. Use the token POSTMARK_API_TEST to check a payload without sending
  3. Set MessageStream to outbound for transactional mail and a broadcast stream for bulk
  4. Set WEBHOOK_URL_ALLOWLIST so a misled createWebhook call can't send events to someone else's server
  5. Keep count + offset under 10,000 on message and bounce searches

Other comparisons with Amazon SES or Postmark API + MCP

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