supermarket

Send email

Postmark

Email delivery service with REST API, SMTP, webhooks and inbound parsing for transactional and broadcast email.

At a glance

Provider
ActiveCampaign
Category
Send email
Type
Hosted API
Pricing model
Monthly plans by email volume, with a per-1,000 rate above the tier1
Free tier
100 emails a month, no overages, no card1
Authentication
Server or account API token in a request header; no OAuth4
Connect via
REST API, SMTP, SDKs, local MCP server3
Read from the provider's pages
2026-11-04
Pricing
  • Pricing model: Monthly plan priced by email volume tier (emails sent and received), plus a per-1,000 rate for emails over the tier
  • Free tier: 100 emails a month, no overages allowed, does not expire
  • Card required for free tier: No
Pricing in full →Tools
  • Official MCP server: Yes, local
  • Address or package: npx -y @activecampaign/postmark-mcp (runs over stdio; source https://github.com/ActiveCampaign/postmark-mcp)
  • Number of tools: 24
Tools in full →Authentication
  • Who creates the account: A person; there is no endpoint that issues tokens, and token creation is a manual step in the web interface
  • Where to get a key: https://account.postmarkapp.com/servers, then the API Tokens tab of a server
  • Other requirements: A verified sender signature or sending domain before real mail sends
Authentication in full →Setup
  • REST API: https://api.postmarkapp.com
  • MCP server: No remote address; local stdio server via npx -y @activecampaign/postmark-mcp
  • OpenAPI spec: https://postmarkapp.com/swagger/server.yml (account API: https://postmarkapp.com/swagger/account.yml)
Setup in full →Limits
  • Numeric request limit: Not published
  • Over-limit response: HTTP 429 when requests exceed acceptable use of the API
  • Daily sending limit: Unlimited emails a day on paid plans
Limits in full →Privacy
  • Data location: United States: a data center outside Chicago and AWS; no EU servers planned
  • Retention: Email content and metadata kept 45 days; bounces, spam complaints and unsubscribes kept indefinitely
  • Used for training: Not published
Privacy in full →

Read from ActiveCampaign’s own pages on 2026-11-04. Every number links to the page a value came from. For agents, the same facts as markdown: /tools/send-email/postmark.md