Resend Email Sender

Send emails via Resend API - no SMTP configuration needed.

Quick Start

1. Configure

Set environment variables in .env:

RESEND_API_KEY=your_resend_api_key
RESEND_FROM=onboarding@resend.dev  # Optional, defaults to Resend test domain

Get API key at https://resend.com

2. Send Email

openclaw run resend-email \
  --to="recipient@example.com" \
  --subject="Hello" \
  --text="Plain text message"

Usage

Basic Text Email

openclaw run resend-email \
  --to="user@example.com" \
  --subject="Notification" \
  --text="Your task is complete."

HTML Email

openclaw run resend-email \
  --to="user@example.com" \
  --subject="Welcome" \
  --html="<h1>Welcome!</h1><p>Thanks for joining.</p>"

Multiple Recipients

openclaw run resend-email \
  --to="user1@example.com,user2@example.com,user3@example.com" \
  --subject="Team Update" \
  --text="Meeting at 3 PM."

CC and BCC

openclaw run resend-email \
  --to="primary@example.com" \
  --cc="manager@example.com" \
  --bcc="archive@example.com" \
  --subject="Report" \
  --text="Please find the attached report."

From Agent

When agent needs to send email:

# Use exec to call the skill
exec openclaw run resend-email \
  --to="recipient@example.com" \
  --subject="Automated Notification" \
  --text="This email was sent automatically by the agent."

Configuration Options

Sender Addresses

• Test domain: onboarding@resend.dev (default, no setup required)
• Custom domain: noreply@yourdomain.com (requires domain verification in Resend dashboard)

Limitations

• Attachments not supported (Resend API requires base64 encoding)
• Rate limits apply based on Resend plan
• Email size limits per Resend documentation

Troubleshooting

"RESEND_API_KEY not configured"

• Set RESEND_API_KEY in .env file or environment

"Failed to send email: Unauthorized"

• Check API key is correct and active
• Verify API key has email sending permission

"Failed to send email: Bad Request"

• Check recipient email format is valid
• Verify from address is verified (for custom domains)

Resources

• scripts/send_email.py - Main email sending script