Top of Funnel - Initial Email Engagement

This section captures the outreach and initial engagement metrics from the email campaign:

Baseline Metrics:

1. Processed Emails:

• Definition: The total number of emails the campaign includes before any suppression or filtering.
  • Calculation: Processed = Sent Emails + Not Sent (Suppressed) Emails
  • Note: This represents all emails the system attempts to handle when sending.

1. Sent Emails:

   • Definition: The number of emails that were successfully sent from your system to recipients’ mail servers.
     • Note: These emails have left your server but may not have yet been delivered to the recipient’s inbox.

2. Not Sent:

• Definition: The number of emails filtered out before being sent due to suppression lists, invalid addresses, or compliance rules.
• Reasons for Suppression:
  • Unsubscribed recipients
  • Invalid or malformed email addresses
  • Previously bounced addresses
  • Recipients who marked previous emails as spam

4. Delivered Emails:

• Definition: The number of emails accepted by the recipient’s mail servers.
  • Calculated as (Delivered Emails ÷ Processed Emails) × 100%.
  • Note: Acceptance by the server doesn’t guarantee placement in the inbox; emails could be routed to spam or other folders.

1. Bounced Emails – Emails that failed to deliver.
   • Soft Bounces: Temporary delivery failures (e.g., mailbox full, server issues).
   • Hard Bounces: Permanent delivery failures (e.g., invalid email addresses). Hard bounces should be removed from future mailings to maintain a healthy email list and be placed on the Suppression list.

Point-in-Time Metrics:

6. Opens:

• Definition: The number of times recipients opened your email, tracked via a tiny invisible image (tracking pixel).
• Unique Opens: Counts each recipient only once, regardless of multiple opens.
• Limitations:
  • Privacy Protections: Features like Apple’s Mail Privacy Protection can inflate open rates by auto-loading images.
  • Image Blocking: If images are blocked, opens may not be tracked.
  • Bot Activity: Security bots may trigger false opens.

7. Clicks:

• Definition: The number of times links within your email were clicked.
• Unique Clicks: Counts each recipient only once, regardless of multiple clicks.
• Note: Click rates are a more reliable engagement metric than opens but can still be affected by bot activity.

8. Spam Reports:

• Definition: The number of times recipients marked your email as spam or junk.
• Impact: High spam report rates can harm your sender reputation and deliverability.

9. Unsubscribes:

• Definition: The number of recipients who opted out of receiving future emails.
• Compliance: Essential for adhering to regulations like CAN-SPAM, GDPR, and CASL.

10. Deferred Emails:

• Definition: Emails temporarily delayed by the recipients’ mail servers, often due to server issues or rate limiting.
• Outcome: Deferred emails may eventually be delivered or result in a bounce after retry attempts.

<aside> 👉

Why Aren’t Open Rates Always Accurate Measures of Campaign Effectiveness?

• Apple’s Mail Privacy Protection (MPP): This feature can artificially inflate open rates by pre-fetching email content, registering it as an open even if the user hasn’t opened the email (introduced with iOS 15 in 2021). Apple has also adjusted pre-fetching timings since April 2024, reducing pixel firing events and directly impacting open rates.
• Bot Activity: Automated systems and spam filters can trigger opens without human interaction, leading to inflated numbers. For example, Gmail uses bots to scan incoming emails for security purposes, which can trigger false opens.
• Email Client Behavior: Some clients allow users to read emails without downloading images (which is how opens are typically tracked), leading to undercounted opens.
• Google Image Caching: Gmail caches images, including tracking pixels used to measure opens. This means multiple opens of the same email by the same user may not be counted, potentially undercounting total opens. However, unique opens are generally tracked accurately. </aside>