Send email

Skill kumard3/lumbox-skills/send-email

Official agent skills for Lumbox — email infrastructure for AI agents (inboxes, OTP extraction, send/reply via REST + MCP).

Install

npx -y skills add kumard3/lumbox-skills --skill send-email

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What its author says it does

Copied from the file, not written here

Send an email from a Lumbox inbox to any recipient. Handles threading, attachments, and returns a message ID for future replies.

SKILL.md

2.1 KB, 562 tokens by cl100k_base, as published. Nobody here has run it

Send an Email

Use this skill when an AI agent needs to send an email - a reply, a notification, a form submission, or outbound agent-to-human communication.

When to use

Agent needs to reply to an email it received
Agent needs to initiate outbound contact (notify a user, file a form)
Agent needs to forward an email

Prerequisites

A Lumbox inbox ID (see the create-lumbox-inbox skill)
LUMBOX_API_KEY environment variable set
Recipient email address

Steps

Call the send endpoint:

curl -X POST "https://api.lumbox.co/v1/inboxes/$INBOX_ID/send" \
  -H "X-API-Key: $LUMBOX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "[email protected]",
    "subject": "Hello from an AI agent",
    "text": "Plain text body.",
    "html": "<p>HTML body.</p>"
  }'

Read the response. You get a message ID that identifies this email for future threading:

{
  "id": "eml_7y3c...",
  "message_id": "<[email protected]>",
  "sent_at": "2026-04-18T10:35:00.000Z"
}

For replies, use the reply endpoint instead - it sets In-Reply-To and References headers correctly so the email threads in the recipient's client:

curl -X POST "https://api.lumbox.co/v1/inboxes/$INBOX_ID/reply" \
  -H "X-API-Key: $LUMBOX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "reply_to_email_id": "eml_of_original",
    "text": "Thanks for the OTP."
  }'

Tips

Sending uses AWS SES under the hood - deliverability is high.
For bulk sends (up to 100 recipients at once), use /v1/send/bulk.
Attachments: include a attachments array with filename and base64 content.
To forward: use /v1/inboxes/:id/forward with the email ID and new recipient.

Related skills

create-lumbox-inbox - provision the sending inbox
wait-for-otp - receive the reply if the recipient sends one back

What ships with it

Read from the repository

Just SKILL.md. No reference files, no scripts.