Many email marketing platforms promote metrics like “99% Delivery Rate” or “Highest Open Rates in the Industry.” But what do those numbers really mean? This article breaks down the difference between Delivery Rate and Open Rate, how they’re measured, and what they actually tell you about your email performance.
Delivery Rate: What It Actually Means
Delivery Rate is one of the most misunderstood metrics in email marketing.
In its strictest definition, Delivery Rate refers to the percentage of emails that were successfully accepted by the recipient’s mail server — for example, Gmail, Outlook, or Yahoo.
Formula:
(Emails Accepted ÷ Emails Sent) × 100
So when a platform claims a “99% Delivery Rate,” it typically means 99% of messages were not rejected at the server level (i.e., they didn’t bounce). However, this does not guarantee that those emails reached the inbox. Messages accepted by the destination server can still be filtered into Spam, Promotions, or Junk folders.
When most marketers talk about “delivery,” they’re actually referring to Inbox Placement Rate — the percentage of messages that land directly in the inbox rather than being filtered. Unfortunately, inbox placement is not directly measurable by ESPs (Email Service Providers) like Keap, since no system has access to a recipient’s private inbox data.
How Keap Protects Delivery
Keap continuously monitors and manages its sending reputation to maintain high deliverability rates across the network.
We do this by:
- Proactive spammer detection and filtering — prevents bad actors from harming shared IP reputation.
- Blocklist monitoring and remediation — Keap works directly with mailbox providers and blocklist operators to resolve issues quickly.
- Ongoing ISP partnerships — maintaining active relationships with major mailbox providers (Google, Microsoft, Yahoo, and others) to ensure compliance and consistent inbox performance.
Deliverability is an ongoing, shared responsibility between Keap and every sender. Following best practices like list hygiene, permission-based sending, and consistent engagement helps maximize your inbox placement.
Open Rate: Understanding the New Reality
Open Rate measures how many recipients opened your email. Traditionally, this is tracked using a hidden tracking pixel (a 1x1 image) embedded in each message. When the image loads, it signals that the email has been opened.
Formula:
(Unique Tracked Opens ÷ Delivered Emails) × 100
Keap places its tracking pixel at the bottom of the email, ensuring a more accurate measure of genuine engagement — the reader must load or scroll through the full message for the open to be registered.
However, since the introduction of Apple Mail Privacy Protection (MPP) and other privacy-focused features, open rate data has become less reliable across the entire email industry:
- Apple devices often auto-load tracking pixels, marking emails as opened even if the user never viewed them.
- This can inflate open rates by up to 40%, depending on your audience composition.
- Gmail and Outlook also use image caching and other privacy mechanisms that affect open tracking accuracy.
Because of these changes, open rates should be viewed as directional indicators rather than absolute measures of engagement.
Click Rate: The More Reliable Metric
Click Rate measures how many recipients clicked on at least one link in your email.
Formula:
(Unique Tracked Clicks ÷ Delivered Emails) × 100
Due to privacy features like MPP, click rates are now a more reliable measure of engagement than opens.
Keap’s system provides accurate click tracking by:
- Filtering out automated security clicks generated by spam filters or link scanners.
- Ensuring only real user interactions are recorded.
As a result, your click metrics in Keap may appear slightly lower than competitors who don’t filter automated clicks — but they are far more accurate and actionable.
Best Practices for Using These Metrics
- Focus on trends, not absolutes: Compare performance across your own campaigns within Keap, not against metrics from other platforms.
- Evaluate relative success: Track open and click rate trends to understand which content, subject lines, or segments perform best.
- Prioritize engagement quality: Good list hygiene, segmentation, and relevant content drive higher inbox placement and conversions.
Summary
Here’s a quick breakdown of what each metric tells you and how reliable it is:
- Delivery Rate: Measures the percentage of emails accepted by recipient servers. This is highly accurate but doesn’t indicate whether the message landed in the inbox or spam.
- Open Rate: Measures the percentage of delivered emails that were opened. Accuracy is moderate and increasingly affected by Apple MPP and image caching.
- Click Rate: Measures the percentage of delivered emails where a recipient clicked a link. This is the most reliable engagement indicator and provides the best signal of actual interaction.
In Short
- A 99% delivery rate means your emails weren’t rejected — not necessarily that they reached the inbox.
- Open rates are useful for identifying trends, not exact engagement.
- Clicks, conversions, and engagement trends provide the most meaningful insights into your email performance.
Looking for extra help?
If you’d like professional guidance with your email practices or recommended tools to improve your email practices and deliverability, check out these trusted partners:
- Email Deliverability specialist training, consulting and software
- List Cleaning
- Form Security
Comments
0 comments
Please sign in to leave a comment.