Be the first to get access to new connectors. Get early access →
ConnectorBay Early access

Mailosaur (BYOK) — connector documentation

  • MCP endpoint: https://byok-mailosaur.connectorbay.com/mcp
  • REST API: POST https://byok-mailosaur.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://byok-mailosaur.connectorbay.com/openapi.json
  • Transport: Streamable HTTP, stateless, MCP specification 2025-06-18 or later
  • Authentication: your own Mailosaur API key, sent in the X-Upstream-Key header of every request (never stored, logged or cached)
  • Health: https://byok-mailosaur.connectorbay.com/health · Tool schemas: https://byok-mailosaur.connectorbay.com/tools.json
  • Publisher: Unify Dynamics LLC · connectorbay.com/byok-mailosaur · agent@connectorbay.com

What Mailosaur (BYOK) is for

Mailosaur (BYOK) lets an AI assistant read your own Mailosaur data through the Mailosaur API with a key you supply (API key). Read-only: 6 tools (list_servers, get_server, list_messages, get_deliverability_report, get_usage_limits, list_usage_transactions). The BYOK key travels with each request, is used for that one call only and is never stored, logged or cached; it is only ever sent to mailosaur.com. Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by Mailosaur. Mailosaur and its logos are trademarks of their owners and are used only to say which service the connector works with.

Ask your assistant things like:

  • "Which Mailosaur inboxes do I have and how many messages are in each?"
  • "How many messages are in Mailosaur server abcd1234?"
  • "What was the latest email that reached my Mailosaur test inbox?"
  • "Does Mailosaur message 77061c9f-da47-4009-9f33-9715a3bbf00c pass SPF, DKIM and DMARC?"
  • "How close am I to my Mailosaur email limit?"
  • "How many emails did my Mailosaur account receive per day this month?"

What it does

  • list_servers: List your Mailosaur servers (virtual inboxes for email and SMS testing) in alphabetical order with id, name, users and message count.
  • get_server: Get one Mailosaur server by id: name, users and message count.
  • list_messages: List message summaries of one server, newest first: id, received time, type (Email or SMS), subject, sender and recipients. Message bodies are not returned.
  • get_deliverability_report: Analyse one received email for deliverability: SPF, DKIM and DMARC results, block-list checks, content issues, DNS records and SpamAssassin score.
  • get_usage_limits: Show account limits and current usage for servers, users, emails, SMS, previews and numbers (needs an account-level key).
  • list_usage_transactions: List the last 31 days of daily usage: emails, SMS and previews per day (needs an account-level key).

BYOK key

You bring your own Mailosaur API key (https://mailosaur.com/app/keys). Your assistant sends it in the X-Upstream-Key header with each request. ConnectorBay uses it for that one call only: it is never stored, logged or cached, never shown in an answer, and it is only sent to mailosaur.com over https, with no redirects followed. Create a key with the fewest permissions the tools need (read-only if the provider offers it), and revoke it at the provider whenever you like.

Data sources

Live from the Mailosaur API (mailosaur.com) with a BYOK key; documentation: https://mailosaur.com/docs/api/. Endpoints checked against that documentation on 2026-10-16.

What it is not

Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by Mailosaur. Mailosaur and its logos are trademarks of their owners and are used only to say which service the connector works with. It is read-only: it never creates, changes, sends or deletes anything in your Mailosaur account.

Built for: Worldwide. Languages: English.