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Email (SMTP) Integration

What It Enables

Send automated emails from your workflows using SMTP:

Prerequisites

How to Connect

Step 1: Get SMTP Credentials

Choose your email provider:

Gmail

  1. Enable 2-factor authentication
  2. Generate App Password: myaccount.google.com/apppasswords
  3. Use App Password (not your regular password)
  4. SMTP Server: smtp.gmail.com
  5. Port: 587 (TLS) or 465 (SSL)

Outlook/Office 365

  1. SMTP Server: smtp.office365.com
  2. Port: 587
  3. Use your email and password
  4. Enable SMTP AUTH in admin center

SendGrid

  1. Create API key in SendGrid dashboard
  2. SMTP Server: smtp.sendgrid.net
  3. Port: 587
  4. Username: apikey
  5. Password: Your API key

Custom SMTP

  1. Get SMTP server address from provider
  2. Get port number (usually 587, 465, or 25)
  3. Get authentication credentials
  4. Check TLS/SSL requirements

Step 2: Add Email Action

  1. In your flow, click “+” to add a step
  2. Search for “Email” or “SMTP”
  3. Select “Send Email” action

Step 3: Configure Connection

  1. Click “Connect” or “+ New Connection”
  2. Enter SMTP details:
    • SMTP Host: Server address
    • SMTP Port: Port number
    • Username: Your email or username
    • Password: Password or API key
    • From Email: Sender address
    • From Name: Sender display name
  3. Click “Test Connection”
  4. Click “Save”

Step 4: Compose Email

  1. To: Recipient email(s)
  2. Subject: Email subject line
  3. Body: Email content (HTML or plain text)
  4. CC/BCC: Optional additional recipients
  5. Attachments: Optional files

Step 5: Test

  1. Click “Test” to send test email
  2. Check recipient inbox (and spam folder)
  3. Verify formatting and content

Email Configuration

Basic Fields

To (Required)

Subject (Required)

Order Confirmation #

Body (Required)

Optional Fields

CC (Carbon Copy)

BCC (Blind Carbon Copy)

Reply-To

Attachments

HTML Email Templates

Simple Template

<html>
<body>
  <h1>Hello !</h1>
  <p>Thank you for your order.</p>
  <p>Order ID: <strong></strong></p>
  <p>Total: $</p>
</body>
</html>

Professional Template

<html>
<head>
  <style>
    body { font-family: Arial, sans-serif; }
    .header { background: #2C3E50; color: white; padding: 20px; }
    .content { padding: 20px; }
    .button { background: #3498db; color: white; padding: 10px 20px; text-decoration: none; }
  </style>
</head>
<body>
  <div class="header">
    <h1>Defense Catalyst</h1>
  </div>
  <div class="content">
    <p>Hi ,</p>
    <p></p>
    <a href="" class="button">Take Action</a>
  </div>
</body>
</html>

Responsive Template

Use inline CSS for better email client compatibility:

<table width="100%" cellpadding="0" cellspacing="0">
  <tr>
    <td align="center">
      <table width="600" cellpadding="20">
        <tr>
          <td style="font-family: Arial; font-size: 16px;">
            Your content here
          </td>
        </tr>
      </table>
    </td>
  </tr>
</table>

Common Errors & Fixes

“Authentication failed”

Cause: Invalid credentials Fix:

  1. Verify username and password are correct
  2. For Gmail, use App Password (not regular password)
  3. Check 2FA is enabled (if required)
  4. Verify SMTP server address is correct

“Connection timeout”

Cause: Cannot reach SMTP server Fix:

  1. Check SMTP server address
  2. Verify port number (587, 465, or 25)
  3. Check firewall isn’t blocking connection
  4. Try different port (TLS vs SSL)

“Relay access denied”

Cause: SMTP server won’t relay for your domain Fix:

  1. Authenticate with valid credentials
  2. Use authorized sender address
  3. Check SMTP server allows relay
  4. Verify sender domain is authorized

“Message rejected”

Cause: Email content or recipient rejected Fix:

  1. Check recipient email is valid
  2. Verify sender email is authorized
  3. Check for spam trigger words
  4. Ensure HTML is valid
  5. Check attachment size limits

“TLS/SSL error”

Cause: Encryption configuration mismatch Fix:

  1. Try port 587 with TLS
  2. Try port 465 with SSL
  3. Check “Require TLS” setting
  4. Update to latest TLS version

“Rate limit exceeded”

Cause: Too many emails sent Fix:

  1. Check provider’s sending limits
  2. Reduce email frequency
  3. Implement delays between sends
  4. Upgrade to higher tier plan

Test Checklist

Tips & Best Practices

Deliverability

Content

Performance

Security

Compliance

Advanced Patterns

Dynamic Content

<p>Hi ,</p>


  <p>As a premium member, you get exclusive benefits!</p>

  <p>Upgrade to premium for more features.</p>

Conditional Sending

Condition: Only send if  is true
Action: Send Email

Email with Attachment

Attachment URL: 
Or
Attachment Data:

Follow-up Sequence

1. Send welcome email immediately
2. Wait 3 days
3. Send tips email
4. Wait 7 days
5. Send survey email

Error Notification

Trigger: Flow fails
Action: Send email to admin
Subject: "Flow Failed: "
Body: Error details and logs

Email Provider Limits

Gmail

Outlook

SendGrid

Custom SMTP

Alternatives

For High Volume

For Marketing

For Transactional

Troubleshooting Deliverability

Emails Going to Spam

Check:

  1. SPF record configured
  2. DKIM signature present
  3. DMARC policy set
  4. Sender reputation good
  5. Content not spammy
  6. Unsubscribe link present

Tools:

Emails Not Delivered

Check:

  1. Recipient email valid
  2. Not on blocklist
  3. SMTP logs for errors
  4. Bounce notifications
  5. Provider sending limits

Example Use Cases

Order Confirmation

New order → Format email → Send confirmation

Daily Report

Schedule (daily) → Generate report → Email to team

Error Alert

Flow fails → Format error details → Email to admin

Welcome Email

New user → Send welcome email → Track engagement

Password Reset

Reset request → Generate token → Email reset link

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