Events tracking

Welcome to the Events Tracking page. This section provides detailed explanations and real-world behaviors for all 9 system-level events tracked by MX18.

Understanding these events helps you measure user engagement, diagnose issues, and comply with email regulations.

1. Processed

This event is triggered when your message is accepted by MX18's application layer for further processing.

This does not guarantee delivery — the message still undergoes checks like suppression, billing limits, domain verification, and warmup compliance.

Example payload

{
  "event": "processed",
  "email": "user@example.com",
  "timestamp": 1717419012,
  "message_id": "abc123@mx18"
}

2. Bounced

A bounce occurs when an email is permanently rejected by the recipient’s server.

Typical reasons include invalid email addresses, domain issues, or mailbox not found.

Common SMTP bounce codes:

550 5.1.1 User unknown
550 5.4.1 Recipient address rejected
554 5.7.1 Relay access denied

Example payload:

{
  "event": "bounce",
  "email": "user@example.com",
  "reason": "550 5.1.1 The email account that you tried to reach does not exist.",
  "status": "5.1.1"
}

3. Dropped

Drop events happen when MX18 intentionally blocks an email before it reaches the MTA due to internal rules such as:

Suppression list match
Invalid sender domain
Billing limits exceeded
Warmup restrictions

These emails do not hit ISP servers and do not affect your sender reputation.

Example payload:

{
  "event": "dropped",
  "email": "user@example.com",
  "reason": "Suppressed due to unsubscribe",
  "mx_drop_type": "suppression"
}

4. Deferred

A message is deferred when we attempt to deliver it to the recipient’s ISP, but fail to get a positive response — even after retrying over a period of time (up to 3 days).

Typical causes: - Recipient inbox full

ISP firewall or greylisting
Temporary network issues

Example payload:

{
  "event": "deferred",
  "email": "user@example.com",
  "reason": "451 4.7.0 Temporary server error. Try again later."
}

5. Delivered

A delivered event means the receiving ISP has accepted the email for delivery.

This does not confirm the recipient has opened or read the email.

Example payload:

{
  "event": "delivered",
  "email": "user@example.com",
  "timestamp": 1717419612
}

6. Open

An open event is recorded when a recipient views your email — tracked via a hidden pixel image embedded by MX18.

Important Note:

Due to Mail Privacy Protection (MPP) and image proxying by Gmail and other ISPs, false opens may be triggered when emails are preloaded by the server.

We are actively working on false open detection and will notify users once released.

Want to disable open tracking for your account or a specific domain? Email support@mx18.com

Example payload:

{
  "event": "open",
  "email": "user@example.com",
  "user_agent": "Mozilla/5.0 iPhone iOS15",
  "timestamp": 1717419655
}

7. Click

A click event occurs when a recipient clicks any link in your email. All links are automatically rewritten and tracked through your branded domain (if set).

Example payload:

{
  "event": "click",
  "email": "user@example.com",
  "url": "https://example.com/promo",
  "timestamp": 1717419690
}

8. Spam report

Spam reports are generated when recipients mark your email as spam in their inbox. We receive this data via Feedback Loops (FBL) from ISPs.

It is recommended to enroll your domain in major ISPs' FBLs during onboarding. Contact support for setup assistance.

Example payload:

{
  "event": "spam_report",
  "email": "user@example.com",
  "timestamp": 1717419700
}

9. Unsubscribe

An unsubscribe event is logged when a user clicks:

The one-click unsubscribe header (used by Gmail, Yahoo, Outlook)
A custom unsubscribe link in your email body

MX18 automatically adds one-click unsubscribe headers for all marketing and promotional emails — except OTPs.

To add an unsubscribe link manually, use the tag:

<a href="|*UNSUBSCRIBE*|">Click here to Unsubscribe</a>

The |UNSUBSCRIBE| tag will be replaced by a unique link at send-time.

Example payload:

{
  "event": "unsubscribe",
  "email": "user@example.com",
  "timestamp": 1717419730
}

Need help?

Have questions about how events are tracked or need help interpreting your stats?

Visit your MX18 Dashboard
Or contact support@mx18.com for assistance