Summary
Unexpected characters appearing at the end of email click tracking URLs, such as curved brackets or extraneous text, can be a frustrating issue for email marketers. This phenomenon, which often seems random, points to underlying technical inconsistencies rather than email deliverability problems. The primary cause frequently lies in how email templates, particularly their plain text versions, are generated and interpreted by various email clients or webhooks.
Key findings
- Plain text rendering: The issue is frequently linked to how emails are rendered in plain text format, where URLs may be wrapped incorrectly without proper spacing.
- Template editor errors: Many problems stem from template editors that generate plain text versions of emails incorrectly, leading to improper URL formatting.
- Inconsistent behavior: The problem can appear inconsistently across different users, ISPs, and even different links within the same email.
- Post-click appearance: While the tracking system (e.g., webhook) might capture the malformed URL, directly clicking the link often leads to the correct, clean URL.
- Impact on tracking: These anomalies can affect the accuracy of click tracking data, even if the user reaches the intended destination.
Key considerations
- Root cause analysis: Investigate your email template generation process, especially for plain text versions, to ensure proper URL encoding and spacing. This is crucial for avoiding issues where unencoded URLs cause problems.
- HTML and plain text synchronization: Ensure that the plain text version accurately reflects the HTML version's links, paying close attention to character placement and spacing around URLs.
- ESPs and client rendering: While the issue might appear with an ESP's tracking, the root cause is often client-side rendering or template generation, rather than the ESP's core click-tracking mechanism (which often involves adding long, encoded strings for tracking).
- Debugging: An ASCII dump of the original email can reveal hidden characters or improper formatting that contribute to these URL anomalies.
What email marketers say
Email marketers grappling with inconsistent URL issues often find themselves checking their internal systems and vendor reports. The prevailing sentiment indicates that these seemingly random characters are not necessarily deliverability blockers but rather data anomalies stemming from how tracking events are captured or how email content is rendered. The focus shifts quickly from network or reputation issues to examining the email's raw code and the specific environment in which the click occurred.
Key opinions
- Webhook observations: Marketers frequently monitor click tracking events through webhooks and report seeing the malformed URLs there.
- Vendor confirmation: Confirmation from ESPs that they also observe these URL anomalies on their backend validates the issue is not just a local viewing problem.
- Inconsistency across clicks: The same user clicking the same link multiple times can yield different URL results, indicating an unpredictable processing or rendering issue.
- Random appearance: The issue tends to be random, affecting various ISPs, users, and even different links (e.g., CTA buttons or hero images) within the same email template.
- Plain text as a culprit: Marketers note that the problem is often tied to users opening emails in plain text format, where template editors might introduce formatting errors.
Key considerations
- Template generation: Review how your email template editor generates plain text versions. Issues like URLs wrapped in brackets without subsequent spaces can lead to appending adjacent text, impacting your click tracking best practices.
- Data integrity: Even if the underlying URL functions, the data captured by your webhook might be skewed, affecting your analytics. Ensure your UTM parameters (see UTMbuilder.com) are not being corrupted.
- Email client variations: Be mindful that different email clients interpret and display plain text emails uniquely. Test your plain text versions across various clients to catch these discrepancies.
- Debugging tools: Utilize ASCII dumps or similar tools to inspect the raw email source for any invisible or improperly encoded characters that could be causing parsing errors.
Marketer view
Marketer from Email Geeks observes inconsistent URL behavior, where click-tracked URLs sometimes end with a curved bracket or other text, even when clicking the same link in the same email.
Marketer view
Marketer from Quora suggests that the seemingly random characters in long URLs are often encoding specific information about the email address or other tracking details for analytics.
What the experts say
Experts in email deliverability and technical email rendering consistently point away from general deliverability issues when confronted with unexpected characters in click tracking URLs. Instead, they highlight potential problems in email coding, client-side rendering, or specific ESP processes. The emphasis is on deep-diving into the email's raw structure and the exact conditions under which the anomalies appear, rather than broad network or reputation concerns. Identifying the precise point of corruption, whether it's hidden characters, mismatched quotes, or string sanitation, is key.
Key opinions
- Code-related issue: Experts believe that such URL issues are typically rooted in code problems within the email, the ESP's system, or the tool used to view tracking data.
- Client or template issues: The problem is more likely client-related or linked to email template/code rather than overall deliverability.
- ASCII dump importance: Reviewing an ASCII dump of the original email is crucial to detect hidden characters that can cause unpredictable software behavior.
- String sanitation: The addition of characters like a closing bracket might be a result of string sanitation, potentially on the ESP's side.
- Consistent client hypothesis: Random occurrences across ISPs and users could indicate a consistent client issue, where certain coding practices (e.g., HTML attribute quoting) frustrate clients.
Key considerations
- Examine HTML structure: Pay close attention to the HTML immediately following the URL in your email templates, including proper closing tags and quote usage around HREF attributes (e.g., <a href='...'> vs. <a href="...">). This can prevent unintended additions or modifications.
- Consistency of appended characters: Determine if the appended characters are always the same (e.g., always a closing parenthesis) or if they vary, as this can point to different underlying causes.
- Isolate the environment: Test emails across various clients and browsers to pinpoint if the issue is tied to a specific rendering environment, which can often explain inconsistent warnings.
- Distinguish from deliverability: Recognize that these issues are typically not related to blocklists or broader email deliverability (like being sent to a spam or junk folder) but rather to specific technical quirks in URL parsing and display.
Expert view
Expert from Email Geeks suggests that an issue with inconsistent URL behavior is unlikely to be related to deliverability and is more probably a client-related problem, or an issue with the email template or code.
Expert view
Expert from SpamResource explains that email service providers often rewrite URLs to include their own unique tracking parameters, which can sometimes appear as random characters to recipients but are essential for gathering analytics data.
What the documentation says
Technical documentation and web standards provide the foundational understanding for why URLs might behave unexpectedly in email click tracking. They emphasize proper URL construction, encoding, and the role of various systems in processing links. Documentation highlights that tracking mechanisms often involve rewriting URLs with additional data, and that email clients and privacy features can further modify these links. Adherence to established RFCs and best practices in email rendering is paramount to avoid unintended character additions.
Key findings
- URI structure: URIs are defined as sequences of characters from a restricted set, implying a need for careful construction to maintain integrity.
- Percent-encoding: Characters outside the unreserved set must be percent-encoded when used in a URI to prevent ambiguity or disallowed characters.
- ESP link wrapping: Email service providers commonly wrap original URLs with redirect URLs that include unique, encoded identifiers for tracking individual clicks.
- System interpretation: Various email clients and web environments apply their own rendering logic, which can lead to unintended character additions due to improper string concatenation or unescaped characters.
- Privacy features: Modern privacy features in messaging and email platforms may actively remove extra information from URLs to prevent tracking (e.g., Apple's privacy features, see Apple Privacy).
Key considerations
- URL encoding standards: Strictly adhere to URL encoding standards (e.g., RFC 3986) for all links within your email content. This ensures that special characters are handled correctly and do not break the URL integrity.
- Plain text fallback: Ensure your plain text email generation accurately represents links without introducing extra characters or wrapping issues, as plain text versions are often consumed by various systems.
- ESP interaction: Understand how your ESP's click tracking mechanism modifies URLs. While their additions are typically intentional and necessary for tracking, they should not interfere with the base URL's integrity.
- Testing across environments: Implement rigorous testing of your email links across a wide range of email clients and devices to catch any rendering or parsing inconsistencies before deployment.
Technical article
Documentation for Apple Privacy states that when sharing links in Messages, additional information added to URLs by some websites is removed to prevent tracking of users.
Technical article
RFC 3986 (URI Generic Syntax) specifies that a Uniform Resource Identifier (URI) is fundamentally a sequence of characters derived from a carefully restricted set, chosen for their general applicability and wide implementability across various systems.
Related resources
9 resources
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