Email component with Credentials

This email component is designed for use with the Mailchimp Transactional API or custom SMTP server.

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Table of Contents

• Description
• Credentials
• Environment variables
• Actions
  • Send Email
• HTML Email Styling Best Practices

Description

This email component is designed for use with the Mailchimp Transactional API or custom SMTP server using SMTP URI.

Credentials

The component supports two authentication and transport methods: Mandrill API and SMTP. At least one of Mandrill API Key or SMTP URI must be configured. If both are provided, SMTP URI takes precedence and emails will be sent via SMTP.

Complete the following fields in the component’s credential section:

• Mandrill API Key - (string, optional): Your key from the Mandrill app settings (required when sending via Mandrill).
• SMTP URI - (string, optional): SMTP connection URI (e.g. smtp://USER:PASS@HOST:PORT or smtps://USER:PASS@HOST:PORT). Required when sending via custom SMTP server.
• Mandrill API Url - (string, optional, https://mandrillapp.com/api/1.0 by default): The URL for the Mandrill API (used only with Mandrill).
• From Email - (string, required): The sender’s email address.
• From Name - (string, optional): The sender’s display name.

Please Note: For the Mandill authentication, you must create a Mailchimp account and generate an API key that will serve as part of the credentials for the Mandrill app.

Environment variables

The component can be configured using the following environmental variables

Actions

Send Email

For each incoming message the component sends an email message via SMTP (if SMTP URI is configured, taking precedence over Mandrill) or via Mandrill using the Send new message API resource.

Configuration Fields

• Do not throw an error when e-mail send failed - (checkbox, optional): If checked, the component will not throw an error when sending fails; details will be provided in the output message. Defaults to false.

Input Metadata

• To - (string, required): The email address(es) for primary recipients; you can provide a comma-separated list.
• Cc - (string, optional): Comma-separated list of email addresses to receive a carbon copy of the mail.
• Bcc - (string, optional): Comma-separated list of email addresses to receive a blind carbon copy of the mail.
• Subject - (string, required): Subject of the email.
• Text Body - (string, optional): The plain text content of the email. If the body is a JSON object or array, it will be automatically stringified. Serves as a fallback for email clients that do not render HTML. Either ‘Text Body’ or ‘HTML Body’ must be provided.
• HTML Body - (string, optional): The HTML content of the email to be sent. Either ‘Text Body’ or ‘HTML Body’ must be provided.
• Attachments - (array, optional): List of attachment objects:
  • Attachment URL - (string, required): URL of the file (from platform storage or external).
  • Filename - (string, required): Name of the attached file as it will appear in the received email.

Input message example:

{
  "to": "recipient@example.com",
  "cc": "manager@example.com",
  "subject": "Sample Notification",
  "textBody": "Hello! Thank you for subscribing.",
  "htmlBody": "<p>Hello! Thank you for subscribing.</p>",
  "attachments": [
    {
      "url": "https://example.com/files/invoice.pdf",
      "name": "invoice.pdf"
    }
  ]
}

Output Metadata

As a result of sending, you will receive an object containing a “results” array with delivery information for each recipient:

• To - (string): The email address of the recipient.
• RecipientType - (string): Type of recipient (to, cc, or bcc).
• Message - (string): The sending status of the recipient (OK or QUEUED on success; REJECTED or INVALID on failure).
• MessageID - (string): The message’s unique identifier.
• SubmittedAt - (string): Timestamp when the message was submitted in ISO format (YYYY-MM-DDTHH:mm:ss.SSSSSSSZ).
• RejectedReason - (string, optional): Rejection reason returned by the mail server (present when Message is REJECTED).
• ErrorCode - (number): Deprecated parameter, always 0.

Output message example:

{
  "results": [
    {
      "To": "recipient@example.com",
      "RecipientType": "to",
      "Message": "OK",
      "MessageID": "c1d10979c1ca441385f64f209d172508",
      "SubmittedAt": "2026-10-16T13:10:00.0000000Z",
      "ErrorCode": 0
    }
  ]
}

HTML Email Styling Best Practices

When providing content for the HTML Body, keep in mind that rendering in email clients (like Gmail, Outlook, or Apple Mail) differs significantly from modern web browsers:

1. CSS Inlining: Many email clients (especially Gmail and older versions of Outlook) strip out <style> blocks located in the <head> for security and performance reasons. For the most reliable results, inline your CSS directly into the HTML tags using the style attribute.
2. Avoid CSS Variables: Email clients do not support CSS variables (e.g., var(--main-color)). Use literal hex codes instead.
3. Table-Based Layouts: While modern browsers use Flexbox or Grid, many email clients still require standard HTML tables (<table>) for complex multi-column layouts to ensure stability.
4. CSS Inlining Support: When sending via Mandrill, this component enables inline_css: true, which attempts to automatically move styles from <style> blocks into element attributes. However, manual inlining is always recommended for critical designs.

An HTML body example with inlined styles:

{
  "to": "email@example.com",
  "subject": "HTML content",
  "textBody": "Hello! Thank you for subscribing.",
  "htmlBody": "<body style=\"margin:0; padding:20px; font-family:Arial,sans-serif; background-color:#f4f4f4;\"><div style=\"background-color:#ffffff; padding:20px; border-radius:5px; box-shadow:0 0 10px rgba(0,0,0,0.1); max-width:600px; margin:0 auto;\"><h1 style=\"color:#333;\">Hello, Recipient!</h1><p style=\"font-size:16px; color:#666; line-height:1.5;\">Thank you for subscribing to our newsletter.</p><a href=\"https://www.example.com\" style=\"display:inline-block; padding:10px 20px; background-color:#007BFF; color:#ffffff; text-decoration:none; border-radius:5px;\">Get Started</a></div></body>"
}