email-notifications（电子邮件通知）

Email Notifications for ServiceNow

ServiceNow notifications are triggered by events and send emails, SMS, or other alerts to users.

Notification Components

Creating Notifications

Basic Notification Structure

Notification: Incident Assigned
├── When to send
│   ├── Table: incident
│   ├── When: Record inserted or updated
│   └── Conditions: assigned_to changes AND is not empty
├── Who will receive
│   ├── Users: ${assigned_to}
│   └── Groups: (optional)
├── What it will contain
│   ├── Subject: Incident ${number} assigned to you
│   ├── Message: HTML body with ${field} references
│   └── Email Template: (optional)
└── Advanced
    ├── Weight: 0 (priority)
    └── Send to event creator: false

Notification Conditions

// Simple field conditions
assigned_to CHANGES
priority = 1
state = 6  // Resolved

// Script condition (ES5 only!)
// Returns true to send, false to skip
(function() {
    // Only notify for VIP callers
    var caller = current.caller_id.getRefRecord();
    return caller.vip == true;
})()

// Advanced condition with multiple checks
(function() {
    // Don't notify on bulk updates
    if (current.sys_mod_count > 100) return false;

    // Only for production CIs
    var ci = current.cmdb_ci.getRefRecord();
    return ci.used_for == 'Production';
})()

Email Templates

Template Variables

<!-- Field references -->
${number}                    <!-- Direct field value -->
${caller_id.name}            <!-- Dot-walked reference -->
${opened_at.display_value}   <!-- Display value -->

<!-- Special variables -->
${URI}                       <!-- Link to record -->
${URI_REF}                   <!-- Reference link -->
${mail_script:script_name}   <!-- Include email script -->

<!-- Conditional content -->
${mailto:assigned_to}        <!-- Mailto link -->

Template Example

<html>
<body style="font-family: Arial, sans-serif;">
  <h2>Incident ${number} - ${short_description}</h2>

  <table border="0" cellpadding="5">
    <tr>
      <td><strong>Priority:</strong></td>
      <td>${priority}</td>
    </tr>
    <tr>
      <td><strong>Caller:</strong></td>
      <td>${caller_id.name}</td>
    </tr>
    <tr>
      <td><strong>Assigned to:</strong></td>
      <td>${assigned_to.name}</td>
    </tr>
    <tr>
      <td><strong>Description:</strong></td>
      <td>${description}</td>
    </tr>
  </table>

  <p>
    <a href="${URI}">View Incident</a>
  </p>

  ${mail_script:incident_history}
</body>
</html>

Email Scripts

Basic Email Script

// Email Script: incident_history
// Table: incident
// Script (ES5 only!):

(function runMailScript(current, template, email, email_action, event) {

    // Build activity history
    var html = '<h3>Recent Activity</h3><ul>';

    var history = new GlideRecord('sys_journal_field');
    history.addQuery('element_id', current.sys_id);
    history.addQuery('name', 'incident');
    history.orderByDesc('sys_created_on');
    history.setLimit(5);
    history.query();

    while (history.next()) {
        html += '<li><strong>' + history.sys_created_on.getDisplayValue() + '</strong>: ';
        html += history.value.substring(0, 200) + '</li>';
    }
    html += '</ul>';

    template.print(html);

})(current, template, email, email_action, event);

Email Script with Attachments

// Add attachments from the record to the email
(function runMailScript(current, template, email, email_action, event) {

    var gr = new GlideRecord('sys_attachment');
    gr.addQuery('table_sys_id', current.sys_id);
    gr.addQuery('table_name', 'incident');
    gr.query();

    while (gr.next()) {
        email.addAttachment(gr);
    }

})(current, template, email, email_action, event);

Dynamic Recipients

// Email Script to add CC recipients dynamically
(function runMailScript(current, template, email, email_action, event) {

    // Add all group members as CC
    var group = current.assignment_group;
    if (!group.nil()) {
        var members = new GlideRecord('sys_user_grmember');
        members.addQuery('group', group);
        members.query();

        while (members.next()) {
            var user = members.user.getRefRecord();
            if (user.email) {
                email.addAddress('cc', user.email, user.name);
            }
        }
    }

})(current, template, email, email_action, event);

Custom Events

Registering a Custom Event

// Event Registration
// Name: x_myapp.incident.escalated
// Table: incident
// Description: Fired when incident is escalated to management
// Fired by: Business Rule

// In Business Rule (ES5 only!)
(function executeRule(current, previous) {

    // Check if escalation occurred
    if (current.escalation > previous.escalation) {
        // Fire custom event
        gs.eventQueue('x_myapp.incident.escalated', current,
            current.escalation.getDisplayValue(),  // parm1
            current.assigned_to.name               // parm2
        );
    }

})(current, previous);

Notification on Custom Event

Notification: Escalation Alert
├── When to send
│   ├── Send when: Event is fired
│   └── Event name: x_myapp.incident.escalated
├── Who will receive
│   └── Users/Groups: Escalation Managers
└── What it will contain
    ├── Subject: Escalation: ${number} - ${event.parm1}
    └── Message: Incident escalated. Assigned to: ${event.parm2}

Recipient Types

Who Will Receive

Recipient Script

// Recipient Script (ES5 only!)
// Returns comma-separated list of emails or sys_ids

(function getRecipients(current, event) {
    var recipients = [];

    // Add the caller
    if (!current.caller_id.nil()) {
        recipients.push(current.caller_id.email.toString());
    }

    // Add VIP's manager
    var caller = current.caller_id.getRefRecord();
    if (caller.vip == true && !caller.manager.nil()) {
        recipients.push(caller.manager.email.toString());
    }

    return recipients.join(',');

})(current, event);

Notification Weight

Priority system for multiple matching notifications:

// Only highest weight notification sends if "Exclude subscribers" checked
// Weight 0 notification beats Weight 10 notification

Digest Notifications

Configuring Digest

Notification: Daily Incident Summary
├── Digest: Checked
├── Digest Interval: Daily
├── Digest Time: 08:00
└── Content: Summary of all incidents

Digest Email Script

// Summarize digest records
(function runMailScript(current, template, email, email_action, event) {

    var count = 0;
    var html = '<table border="1" cellpadding="5">';
    html += '<tr><th>Number</th><th>Description</th><th>Priority</th></tr>';

    // 'current' is a GlideRecord with all digest records
    while (current.next()) {
        count++;
        html += '<tr>';
        html += '<td>' + current.number + '</td>';
        html += '<td>' + current.short_description + '</td>';
        html += '<td>' + current.priority.getDisplayValue() + '</td>';
        html += '</tr>';
    }
    html += '</table>';
    html += '<p>Total: ' + count + ' incidents</p>';

    template.print(html);

})(current, template, email, email_action, event);

Outbound Email Configuration

Email Properties

// System Properties for email
glide.email.smtp.active          // Enable/disable outbound email
glide.email.smtp.host            // SMTP server
glide.email.smtp.port            // SMTP port (usually 25 or 587)
glide.email.default.sender       // Default from address
glide.email.test.user            // Test recipient (all emails go here)

Testing Notifications

// Background Script to test notification (ES5 only!)
var gr = new GlideRecord('incident');
gr.get('sys_id_here');

// Fire event to trigger notification
gs.eventQueue('incident.assigned', gr,
    gr.assigned_to.getDisplayValue(),
    gs.getUserDisplayName());

gs.info('Event queued for incident: ' + gr.number);

Best Practices

1. Use Templates - Reuse layouts across notifications
2. Test Thoroughly - Use test user property during development
3. Consider Digests - For high-volume notifications
4. Weight Carefully - Prevent duplicate emails
5. ES5 Only - All scripts must be ES5 compliant
6. Limit Recipients - Don't spam large groups
7. Include Context - Provide enough info to act without login
8. Mobile-Friendly - Keep HTML simple for mobile clients

Common Issues