{
  "from": {
    "address": "noreply@yourdomain.com",
    "name": "Your App"
  },
  "to": [
    {
      "email_address": {
        "address": "user@example.com",
        "name": "User"
      }
    }
  ],
  "subject": "Welcome to Our Service",
  "htmlbody": "<h1>Welcome!</h1><p>Thank you for signing up.</p>"
}

Then run:

curl -s "https://api.zeptomail.com/v1.1/email" -X POST --header "Authorization: Zoho-enczapikey $ZEPTOMAIL_TOKEN" --header "Content-Type: application/json" -d @/tmp/zeptomail_request.json

2. Send Plain Text Email

Write to /tmp/zeptomail_request.json:

{
  "from": {
    "address": "noreply@yourdomain.com",
    "name": "Your App"
  },
  "to": [
    {
      "email_address": {
        "address": "user@example.com",
        "name": "User"
      }
    }
  ],
  "subject": "Your OTP Code",
  "textbody": "Your one-time password is: 123456\n\nThis code expires in 10 minutes."
}

Then run:

curl -s "https://api.zeptomail.com/v1.1/email" -X POST --header "Authorization: Zoho-enczapikey $ZEPTOMAIL_TOKEN" --header "Content-Type: application/json" -d @/tmp/zeptomail_request.json

3. Send Email with Tracking

Enable open and click tracking:

Write to /tmp/zeptomail_request.json:

{
  "from": {
    "address": "noreply@yourdomain.com",
    "name": "Your App"
  },
  "to": [
    {
      "email_address": {
        "address": "user@example.com",
        "name": "User"
      }
    }
  ],
  "subject": "Order Confirmation #12345",
  "htmlbody": "<p>Your order has been confirmed. <a href=\"https://example.com/track\">Track your order</a></p>",
  "track_clicks": true,
  "track_opens": true,
  "client_reference": "order-12345"
}

Then run:

curl -s "https://api.zeptomail.com/v1.1/email" -X POST --header "Authorization: Zoho-enczapikey $ZEPTOMAIL_TOKEN" --header "Content-Type: application/json" -d @/tmp/zeptomail_request.json

4. Send to Multiple Recipients (CC/BCC)

Write to /tmp/zeptomail_request.json:

{
  "from": {
    "address": "noreply@yourdomain.com",
    "name": "Your App"
  },
  "to": [
    {
      "email_address": {
        "address": "user1@example.com",
        "name": "User 1"
      }
    }
  ],
  "cc": [
    {
      "email_address": {
        "address": "user2@example.com",
        "name": "User 2"
      }
    }
  ],
  "bcc": [
    {
      "email_address": {
        "address": "admin@example.com",
        "name": "Admin"
      }
    }
  ],
  "subject": "Team Update",
  "htmlbody": "<p>Here is the latest update for the team.</p>",
  "reply_to": [
    {
      "address": "support@yourdomain.com",
      "name": "Support"
    }
  ]
}

Then run:

curl -s "https://api.zeptomail.com/v1.1/email" -X POST --header "Authorization: Zoho-enczapikey $ZEPTOMAIL_TOKEN" --header "Content-Type: application/json" -d @/tmp/zeptomail_request.json

5. Send Email with Attachment (Base64)

# Encode file to base64
FILE_CONTENT=$(base64 -i /path/to/file.pdf)

Write to /tmp/zeptomail_request.json:

{
  "from": {
    "address": "noreply@yourdomain.com",
    "name": "Your App"
  },
  "to": [
    {
      "email_address": {
        "address": "user@example.com",
        "name": "User"
      }
    }
  ],
  "subject": "Your Invoice",
  "htmlbody": "<p>Please find your invoice attached.</p>",
  "attachments": [
    {
      "name": "invoice.pdf",
      "mime_type": "application/pdf",
      "content": "${FILE_CONTENT}"
    }
  ]
}

Then run:

curl -s "https://api.zeptomail.com/v1.1/email" -X POST --header "Authorization: Zoho-enczapikey $ZEPTOMAIL_TOKEN" --header "Content-Type: application/json" -d @/tmp/zeptomail_request.json

6. Send Email with Inline Image

# Encode image to base64
IMAGE_CONTENT=$(base64 -i /path/to/logo.png)

Write to /tmp/zeptomail_request.json:

{
  "from": {
    "address": "noreply@yourdomain.com",
    "name": "Your App"
  },
  "to": [
    {
      "email_address": {
        "address": "user@example.com",
        "name": "User"
      }
    }
  ],
  "subject": "Newsletter",
  "htmlbody": "<p><img src='cid:logo'/></p><p>Welcome to our newsletter!</p>",
  "inline_images": [
    {
      "cid": "logo",
      "name": "logo.png",
      "mime_type": "image/png",
      "content": "${IMAGE_CONTENT}"
    }
  ]
}

Then run:

curl -s "https://api.zeptomail.com/v1.1/email" -X POST --header "Authorization: Zoho-enczapikey $ZEPTOMAIL_TOKEN" --header "Content-Type: application/json" -d @/tmp/zeptomail_request.json

7. Send Templated Email

Use pre-defined templates with merge fields:

Write to /tmp/zeptomail_request.json:

{
  "template_key": "your-template-key",
  "from": {
    "address": "noreply@yourdomain.com",
    "name": "Your App"
  },
  "to": [
    {
      "email_address": {
        "address": "user@example.com",
        "name": "User"
      }
    }
  ],
  "merge_info": {
    "user_name": "John",
    "order_id": "12345",
    "total": "$99.00"
  }
}

Then run:

curl -s "https://api.zeptomail.com/v1.1/email/template" -X POST --header "Authorization: Zoho-enczapikey $ZEPTOMAIL_TOKEN" --header "Content-Type: application/json" -d @/tmp/zeptomail_request.json

Template example (in ZeptoMail dashboard):

<p>Hi {{user_name}},</p>
<p>Your order #{{order_id}} totaling {{total}} has been shipped!</p>

8. Batch Send (Multiple Recipients)

Send to up to 500 recipients with personalized merge fields:

Write to /tmp/zeptomail_request.json:

{
  "from": {
    "address": "noreply@yourdomain.com",
    "name": "Your App"
  },
  "subject": "Your Monthly Report - {{month}}",
  "htmlbody": "<p>Hi {{name}},</p><p>Here is your report for {{month}}.</p>",
  "to": [
    {
      "email_address": {
        "address": "user1@example.com",
        "name": "User 1"
      },
      "merge_info": {
        "name": "Alice",
        "month": "December"
      }
    },
    {
      "email_address": {
        "address": "user2@example.com",
        "name": "User 2"
      },
      "merge_info": {
        "name": "Bob",
        "month": "December"
      }
    }
  ]
}

Then run:

curl -s "https://api.zeptomail.com/v1.1/email/batch" -X POST --header "Authorization: Zoho-enczapikey $ZEPTOMAIL_TOKEN" --header "Content-Type: application/json" -d @/tmp/zeptomail_request.json

9. Batch Send with Template

Write to /tmp/zeptomail_request.json:

{
  "template_key": "your-template-key",
  "from": {
    "address": "noreply@yourdomain.com",
    "name": "Your App"
  },
  "to": [
    {
      "email_address": {
        "address": "user1@example.com",
        "name": "User 1"
      },
      "merge_info": {
        "user_name": "Alice",
        "code": "ABC123"
      }
    },
    {
      "email_address": {
        "address": "user2@example.com",
        "name": "User 2"
      },
      "merge_info": {
        "user_name": "Bob",
        "code": "XYZ789"
      }
    }
  ]
}

Then run:

curl -s "https://api.zeptomail.com/v1.1/email/template/batch" -X POST --header "Authorization: Zoho-enczapikey $ZEPTOMAIL_TOKEN" --header "Content-Type: application/json" -d @/tmp/zeptomail_request.json

Response Format

Success Response

{
  "data": [
  {
  "code": "EM_104",
  "additional_info": [],
  "message": "OK"
  }
  ],
  "message": "OK",
  "request_id": "abc123..."
}

Error Response

{
  "error": {
  "code": "TM_102",
  "details": [
  {
  "code": "TM_102",
  "message": "Invalid email address",
  "target": "to"
  }
  ],
  "message": "Invalid request"
  },
  "request_id": "abc123..."
}

Common Error Codes

Code	Description
TM_101	Authentication failed (invalid token)
TM_102	Invalid request parameters
TM_103	Domain not verified
TM_104	Rate limit exceeded
EM_104	Success

Guidelines

Transactional only - Do not use for marketing or bulk promotional emails
Verify domain first - Sender address must be from a verified domain
Size limit - Total email size (headers + body + attachments) must not exceed 15 MB
Batch limit - Maximum 500 recipients per batch request
Use templates - For consistent emails, create templates in the dashboard
Track reference - Use client_reference to correlate emails with your transactions
TLS required - API only supports TLS v1.2+

zeptomail

Troubleshooting

How to Use

1. Send Basic Email