mailsac API Specification

Name: mailsac API Specification API
Brand: mailsac API Specification
Availability: InStock

★ Only Publicly Available OpenAPI DocumentCommunicationsEmail DeliveryapiKey47 EndpointsREST

For Agents

Drive disposable and reserved Mailsac inboxes at scale: bulk-reserve addresses, fetch messages with attachments, manage owned domains, and receive inbound webhooks. Used by agents that automate email-based workflows and large QA suites.

Connect the mailsac API Specification to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the mailsac API Specification, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.

Install Jentic One Beta (Self-Hosted)

Jentic One Host machine

# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh

Agent machine

# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register       # connects your agent to your Jentic One instance

Jentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.

Capabilities

What an agent can do with mailsac API Specification API.

Bulk-reserve up to 50 enhanced email addresses in a single call

Validate up to 50 addresses at once before triggering outbound sends

Fetch attachments by content ID and stream their bytes back to the caller

Manage owned domains and verify DNS records that route mail to Mailsac

GET STARTED

Start building with mailsac API Specification API

Explore with Jentic

View OpenAPI Document

Jentic publishes the only available OpenAPI document for mailsac API Specification, keeping it validated and agent-ready.

Jentic publishes the only available OpenAPI specification for mailsac API Specification, keeping it validated and agent-ready. The full Mailsac API exposes 47 endpoints covering address reservation in bulk, message retrieval and statistics, attachment download, custom domain management, account information, and inbound webhooks. It is built around the X-API-Key header and supports websocket message streams alongside the REST surface, making it suitable for high-volume QA harnesses and inbound-mail processing pipelines.

Use Cases

Patterns agents use mailsac API Specification API for, with concrete tasks.

★ High-Volume QA Test Harness

Large continuous-integration suites need hundreds of fresh inboxes per run without rate-limiting smaller fleets. The Mailsac bulk reservation endpoint allocates up to 50 private addresses in a single call and the bulk validation endpoint screens outbound recipient lists in one round trip. Test runners can prepare a clean fleet at the start of a job and release everything at the end, keeping inbox state isolated per run.

Call POST /private-addresses-bulk to reserve 50 addresses, run the test job, then DELETE each address to release the fleet.

Custom Domain Inbound Mail Capture

Teams that own a domain on Mailsac can receive every message addressed to that domain at any inbox they have not pre-reserved. The domain endpoints expose verification status, MX configuration, and message listings across all inboxes on the domain. This supports inbound-mail features in production apps as well as wide-net QA scenarios where the test address is generated dynamically.

Verify the custom domain on the Mailsac account, list every message delivered to it in the last hour, and forward the parsed bodies to the inbound processor.

Attachment-Aware Email Processing

Workflows that test PDF receipts, image-based notifications, or signed-document emails need access to the binary parts of a message. The Mailsac attachment endpoints return the list of parts on a message and stream the bytes for any single part by content ID, enabling test runners to assert on attachment count, MIME type, and content directly. Header parsing and raw SMTP retrieval round out the inspection surface.

List attachments on the most recent message, download the PDF part by content ID, and verify the byte-count and MIME type match the expectation.

AI Agent Inbound-Mail Loop

Agents that handle inbound mail (support routing, automated triage, lead enrichment) need a reliable inbox surface they can poll or subscribe to. Through Jentic the agent searches for the relevant Mailsac operation, loads the input schema, and executes the call with credentials served from the Jentic vault. Webhooks and websockets remove the need for tight polling loops in agent runtimes.

Use Jentic to register a webhook on the agent's reserved address, then process each inbound payload by extracting subject, sender, and body for triage.

Key Endpoints

47 endpoints — jentic publishes the only available openapi specification for mailsac api specification, keeping it validated and agent-ready.

METHOD

PATH

DESCRIPTION

GET

/addresses

List all enhanced email addresses

POST

/addresses/{email}

Reserve a private email address

POST

/private-addresses-bulk

Reserve multiple enhanced addresses

GET

/addresses/{email}/messages

List messages for an email inbox

GET

/raw/{email}/{messageId}

Get original SMTP message

POST

/validations/addresses

Validate up to 50 email addresses

GET

/addresses/{email}/message-count

Count messages for an email inbox

GET

/addresses

List all enhanced email addresses

POST

/addresses/{email}

Reserve a private email address

POST

/private-addresses-bulk

Reserve multiple enhanced addresses

GET

/addresses/{email}/messages

List messages for an email inbox

GET

/raw/{email}/{messageId}

Get original SMTP message

Why though Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

The X-API-Key value is stored encrypted in the Jentic vault. Agents receive a scoped execution token and Jentic injects the header on each call — raw keys never leave the vault.

Intent-based discovery

Agents search by intent (e.g., 'bulk reserve disposable inboxes') and Jentic returns the right Mailsac endpoint with its input schema, removing the need to browse the 47-operation surface manually.

Time to first call

Direct Mailsac integration with bulk and webhook flows: 1-2 days. Through Jentic: under 1 hour — search, load schema, execute.

Related APIs

Alternatives and complements available in the Jentic catalogue.

Complementary

Mailsac API

Smaller 16-endpoint Mailsac spec covering the core inbox-fetch surface.

Choose this when you only need basic message read and webhook registration without bulk or domain management.

Alternative

Mailtrap Email Sending API

Mailtrap provides sandbox SMTP and sending APIs for the same email-testing problem space.

Choose Mailtrap when you need to capture outbound mail in a sandbox rather than receive at a public disposable address.

Complementary

Postmark Server API

Postmark sends transactional mail; Mailsac verifies the resulting message in tests.

Pair Postmark for outbound delivery with Mailsac for inbox-side assertion in end-to-end tests.

FAQs

Specific to using mailsac API Specification API through Jentic.

Why is there no official OpenAPI spec for mailsac API Specification?

Mailsac does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call mailsac API Specification via structured tooling. It is validated against the live API and kept up to date. Get started at https://app.jentic.com/sign-up.

What authentication does the Mailsac full API use?

Mailsac uses an API key passed in the X-API-Key header (also accepted as a query parameter). Through Jentic the key lives in the encrypted vault and is injected at execute time, so the raw value never reaches the agent runtime.

Can I reserve many Mailsac addresses at once?

Yes. POST /private-addresses-bulk reserves up to 50 enhanced addresses in a single call, and POST /validations/addresses validates up to 50 addresses in one request.

How do I download an attachment from a Mailsac message?

List the parts on the message via the addresses messages endpoint, then call the attachment-by-content-ID endpoint to stream the bytes for the part you need.

What are the rate limits for the Mailsac full API?

The OpenAPI spec does not declare numeric rate limits — they are tied to your Mailsac plan. Check the account dashboard at mailsac.com for the current quota before high-volume runs.

How do I subscribe to inbound messages through Jentic?

Run pip install jentic, search 'register inbound mail webhook', load the schema for POST /addresses/{email}/webhooks, and execute with the reserved address and your callback URL. Jentic handles the X-API-Key injection.