From antigravity-awesome-skills
Configures or troubleshoots Mailtrap live email sending via Email API, SMTP, transactional streams, bulk streams, or batches.
How this skill is triggered — by the user, by Claude, or both
Slash command
/antigravity-awesome-skills:mailtrap-sending-emailsThe summary Claude sees in its skill listing — used to decide when to auto-load this skill
Mailtrap sends live email over **Email API** (REST) or **SMTP**. Two **streams** apply for API/SMTP: **Transactional** (non-promotional, app-generated) and **Bulk** (**promotional** / marketing volume). **Batch** is not a third stream: it is how you submit **many messages in one request** on whichever stream matches the content. **Campaigns** are a separate product path for promotional mail to ...
Mailtrap sends live email over Email API (REST) or SMTP. Two streams apply for API/SMTP: Transactional (non-promotional, app-generated) and Bulk (promotional / marketing volume). Batch is not a third stream: it is how you submit many messages in one request on whichever stream matches the content. Campaigns are a separate product path for promotional mail to Mailtrap contacts. Pair this sheet with the Transactional / Bulk developer pages when building or debugging integrations (including with AI-assisted coding).
Use when integrating, configuring, or troubleshooting Mailtrap live email sending with Email API, SMTP, transactional streams, bulk streams, or batch requests.
Preferred order:
POST to /api/send or /api/batch with JSON).| Approach | Use when |
|---|---|
| Transactional, single message | Email generated by your app (password resets, receipts, notifications, alerts). One logical message per POST https://send.api.mailtrap.io/api/send |
| Bulk | Promotional email to contacts that you manage on your side and send at volume through Mailtrap. Not the same as "batch": bulk is the stream, not the batch endpoint. |
| Batch | You have multiple different messages to hand off at the same time (up to 500 per request). Cuts HTTP overhead; can be applied to both transactional and bulk |
| Campaigns | Promotional email to recipients stored as Mailtrap contacts, using Mailtrap Campaigns (audiences, scheduling, reporting in the product). Recommended to avoid implementing contact management and email sending logic; requires UI setup before sends flow—this skill does not replace that workflow. |
Before generating SDK code: read the README of the relevant SDK repository linked in the SDKs section below for current method signatures, constructor options, and examples. Do not rely on memory.
Related skills: mailtrap-testing-with-sandbox (safe testing) and mailtrap-setting-up-sending-domain (verification before send).
mailtrap-testing-with-sandbox).| Stream | Send Endpoint | Batch Endpoint | Authorization Header |
|---|---|---|---|
| Transactional | POST https://send.api.mailtrap.io/api/send | POST https://send.api.mailtrap.io/api/batch | Authorization: Bearer $MAILTRAP_API_TOKEN |
| Bulk (promotional / marketing volume) | POST https://bulk.api.mailtrap.io/api/send | POST https://bulk.api.mailtrap.io/api/batch | Authorization: Bearer $MAILTRAP_API_TOKEN |
| Setting | Transactional | Bulk |
|---|---|---|
| Host | live.smtp.mailtrap.io | bulk.smtp.mailtrap.io |
| Port | 587 (also 25, 2525, 465 with SSL) | 587 (also 25, 2525, 465 with SSL) |
| Username | api | api |
| Password | API token ($MAILTRAP_API_TOKEN) | API token ($MAILTRAP_API_TOKEN) |
Use $MAILTRAP_API_TOKEN in either Authorization: Bearer ... or Api-Token: .... The same token works on both send.api.mailtrap.io and bulk.api.mailtrap.io as long as its scope covers the stream. Store tokens in environment variables or a secrets manager and rotate them when access changes.
| Scope | Limit | Window |
|---|---|---|
| Sending API (per token) | 150 requests | 10 seconds |
Use backoff on 429.
Typical fields include from, to, subject, and text and/or html. Optional: category, custom_variables. Exact request bodies: Transactional send and Bulk send.
curl)Transactional send (send.api.mailtrap.io):
curl -X POST https://send.api.mailtrap.io/api/send \
-H "Authorization: Bearer $MAILTRAP_API_TOKEN" \
-H "Content-Type: application/json" \
-d '{
"from": {"email": "hello@yourdomain.com", "name": "Your App"},
"to": [{"email": "user@example.com"}],
"subject": "Hello",
"text": "Plain text body"
}'
Bulk stream uses the same path and JSON shape on the bulk host (same env var; the token only needs bulk-stream scope):
curl -X POST https://bulk.api.mailtrap.io/api/send \
-H "Authorization: Bearer $MAILTRAP_API_TOKEN" \
-H "Content-Type: application/json" \
-d '{
"from": {"email": "hello@yourdomain.com", "name": "Your App"},
"to": [{"email": "user@example.com"}],
"subject": "Promotional",
"html": "<p>HTML body</p>"
}'
Batch (array of messages; up to 500 per request — see API docs for full schema):
curl -X POST https://send.api.mailtrap.io/api/batch \
-H "Authorization: Bearer $MAILTRAP_API_TOKEN" \
-H "Content-Type: application/json" \
-d '{"messages":[{"from":{"email":"a@example.com"},"to":[{"email":"b@example.com"}],"subject":"One","text":"..."}]}'
Use template_uuid and template_variables instead of raw text/html to use a template hosted by Mailtrap. Minimal example:
curl -X POST https://send.api.mailtrap.io/api/send \
-H "Authorization: Bearer $MAILTRAP_API_TOKEN" \
-H "Content-Type: application/json" \
-d '{
"from": {"email": "hello@yourdomain.com", "name": "Your App"},
"to": [{"email": "user@example.com"}],
"template_uuid": "your-template-uuid",
"template_variables": {"user_name": "Jane"}
}'
Use the same API operations as non-template sends.
Mailtrap automatically manages suppressions for addresses that hard bounce, report spam, or unsubscribe, and will not send emails to these suppressed recipients again. For details, see the Suppressions documentation.
| Mistake | Fix |
|---|---|
| Confusing batch with bulk | Batch = many messages in one /api/batch request. Bulk = promotional stream/host and token |
| Promotional API mail on transactional host | Use bulk base URL and bulk token for promotional content you generate in code |
Bulk traffic on send.api.mailtrap.io | Promotional/bulk stream uses bulk.api.mailtrap.io |
| Using sandbox SMTP host for live sending | Live sending uses live.smtp.mailtrap.io or bulk.smtp.mailtrap.io |
| SMTP username is an email address | Username is api; password is the API token |
| Sending before domain is verified | Complete Sending Domains setup and compliance (see mailtrap-setting-up-sending-domain) |
| Guessing SDK API from memory | Read the SDK README and OpenAPI-linked examples; do not invent constructors or method names |
| Choosing SMTP first for a greenfield app | Prefer platform integration if one exists, then SDK, then HTTP API; SMTP only when necessary (see How to integrate) |
npx claudepluginhub sickn33/antigravity-awesome-skills --plugin antigravity-bundle-aas-privacy-compliance-engineeringCaptures outbound email in Mailtrap Email Sandbox for dev, staging, and CI testing. Supports SMTP and HTTP API for inspecting bodies, headers, attachments, and spam checks.
Automates Postmark emails via Rube MCP: send templated batch emails, manage templates, monitor delivery stats and bounces. Requires active Postmark connection.
Sends transactional emails via the Resend API, manages templates, webhooks, domains, contacts, broadcasts, and automations. Use when working with Resend email infrastructure.