When a SaaS company noticed their email click rates had dropped 40% overnight, they panicked. Had their content become irrelevant? Were emails going to spam? The actual cause was simpler: their click tracking domain's SSL certificate had expired. Every tracked link was throwing security warnings, and users weren't clicking through.
Click tracking is one of the most valuable email analytics tools available. Unlike open tracking, which is increasingly unreliable, click tracking captures deliberate user actions. But it's not without complexity. Understanding how it works helps you use it effectively and avoid the pitfalls.
How click tracking works
The mechanism is straightforward: replace every link in your email with a redirect URL that passes through your tracking system.
When you compose an email with a link to https://yoursite.com/pricing, the email platform rewrites it to something like https://track.emailservice.com/click/abc123. When the recipient clicks, they hit the tracking server first. The server logs the click—who clicked, when, which link—then immediately redirects to the original destination.
The redirect happens so fast that users rarely notice. They click a link and arrive at the expected page. Behind the scenes, you've captured valuable data about their engagement.
The tracking URL typically encodes several pieces of information: which email campaign, which recipient, which specific link (if there are multiple), and authentication tokens to prevent tampering. This lets you attribute clicks precisely.
Why click tracking is more reliable than open tracking
Click tracking has significant advantages over open tracking for measuring engagement.
Clicks require deliberate action. Opening an email might happen automatically (prefetching, preview panes), but clicking a link requires the user to actively engage. This makes clicks a stronger signal of genuine interest.
Privacy features don't affect clicks the same way. Apple's Mail Privacy Protection prefetches images, inflating open rates. But it doesn't click links. Click data remains accurate regardless of privacy settings.
Clicks can't be blocked like images. Users who disable image loading still see and can click links. You might miss their opens, but you'll capture their clicks.
Clicks indicate specific interest. An open tells you someone viewed the email. A click tells you which content interested them enough to take action. This specificity is valuable for understanding what resonates.
Click tracking implementation details
Email platforms handle click tracking automatically, but understanding the implementation helps you troubleshoot issues.
Link rewriting happens at send time. The platform scans your email content, identifies links, and replaces each with a tracking URL. The original URL is encoded in the tracking URL or stored in a database keyed by a unique identifier.
The tracking domain matters for deliverability. If your tracking URLs use a domain with poor reputation, it can affect whether your emails reach the inbox. Many platforms let you use a custom tracking domain (like links.yourcompany.com) to maintain brand consistency and reputation control.
HTTPS is essential. Tracking URLs should always use HTTPS. Mixed content warnings (HTTPS email linking to HTTP tracker) cause problems. Security-conscious users won't click HTTP links. And browsers increasingly block or warn about non-secure redirects.
Redirect speed affects user experience. The tracking server should respond in milliseconds. Slow redirects frustrate users and can cause them to abandon the click. Good email platforms optimize their tracking infrastructure for speed.
What click data tells you
Click tracking provides rich data for understanding email engagement.
Click-through rate (CTR) measures what percentage of recipients clicked any link. This is your primary engagement metric—more reliable than open rate and more meaningful than delivery rate.
Click-to-open rate (CTOR) measures clicks as a percentage of opens. This indicates how compelling your content was to people who actually read the email. A high open rate with low CTOR suggests your subject line works but your content doesn't.
Link-level data shows which specific links got clicks. If you have three CTAs and one gets 80% of clicks, that tells you something about what your audience wants. Use this to optimize future emails.
Click timing reveals when people engage. Do clicks happen immediately after sending, or do they trickle in over days? This informs your sending schedule and follow-up timing.
Geographic and device data from clicks (via IP and user agent) shows where and how people engage. Mobile-heavy audiences need mobile-optimized landing pages.
Security considerations
Click tracking introduces security considerations that both senders and recipients should understand.
Phishing exploits click tracking patterns. Attackers create emails with tracking-style URLs that look legitimate but lead to malicious sites. Users trained to expect redirect URLs might not notice when one leads somewhere dangerous.
URL obfuscation hides destinations. Recipients can't easily see where a tracked link goes without clicking it. Hovering shows the tracking URL, not the destination. This reduces transparency and can erode trust.
Link validation by security tools can trigger false clicks. Corporate email security systems often "click" links to check for malware. This can inflate click metrics and, in some cases, trigger unintended actions if links aren't idempotent.
Tracking URLs can leak information. If someone forwards your email, the tracking URL still contains the original recipient's identifier. Clicks from the forwarded copy might be attributed to the wrong person.
Deliverability implications
Click tracking affects deliverability in ways you should consider.
Tracking domain reputation matters. If your tracking domain is flagged as suspicious—maybe it's shared with spammers, or it's been used in phishing—your emails suffer. Custom tracking domains give you control over this reputation.
URL shorteners and redirects can trigger spam filters. Some filters are suspicious of redirect chains. Using well-established tracking domains from reputable email providers mitigates this.
Broken tracking links hurt engagement metrics and user experience. If your tracking infrastructure has problems, links don't work, users get frustrated, and you lose the engagement data you were trying to capture.
Link density affects spam scoring. Emails with many tracked links might score higher on spam metrics. Balance your tracking needs with deliverability considerations.
When not to track clicks
Click tracking isn't always appropriate.
Transactional emails often shouldn't track clicks. A password reset link should go directly to the reset page, not through a tracking redirect. Adding latency or potential failure points to critical user flows is risky.
Sensitive links might warrant direct URLs. If you're linking to confidential documents or secure portals, adding a tracking intermediary might raise security concerns or violate compliance requirements.
Plain text emails can't easily track clicks. The tracking URL would be visible in full, looking suspicious and unprofessional. If you send plain text, accept that click tracking won't work well.
Some recipients object to tracking. Privacy-conscious users might avoid clicking tracked links on principle. For certain audiences, direct links build more trust than tracked ones.
Best practices
Maximize the value of click tracking while minimizing downsides.
Use a custom tracking domain that you control. This protects your reputation and provides branding consistency. Set it up with proper SSL and monitor its health.
Keep tracking infrastructure reliable. Broken click tracking is worse than no click tracking. Monitor your tracking endpoints and have alerting for failures.
Don't over-track. You don't need to track every link. Focus on CTAs and key content links. Tracking navigation links or footer links adds noise without insight.
Combine click data with other metrics. Clicks alone don't tell the full story. Combine with conversion data, revenue attribution, and qualitative feedback for complete understanding.
Respect user privacy. Be transparent about tracking in your privacy policy. Provide ways for users to opt out if required by regulations or requested.
Frequently asked questions
Do click tracking URLs affect SEO?
Not directly—email links don't pass SEO value regardless of tracking. But if tracked links are indexed (they shouldn't be), the redirects could cause confusion. Properly configured tracking domains use noindex directives.
Can users see where a tracked link goes before clicking?
Not easily. Hovering shows the tracking URL. Some email clients show the destination after the redirect, but most don't. This is a transparency tradeoff inherent to click tracking.
Why do my click rates seem inflated?
Security scanners and bots often 'click' links to check for malware. Some email platforms filter out known bot traffic, but it's imperfect. Look for patterns like clicks from data center IPs or clicks on every link simultaneously.
Should I track clicks in transactional emails?
Generally no for critical links like password resets or verification. For informational transactional emails (order confirmations with product links), tracking can be appropriate. Prioritize user experience over analytics for critical flows.