Summary
Email deliverability is significantly impacted by how links are managed within your campaigns. While generic public link shorteners, such as Bitly or TinyURL, are widely discouraged due to their frequent abuse by spammers and the resulting negative impact on sender reputation, Email Service Providers (ESPs) employ a distinct and generally safe method for link tracking. ESPs like Mailchimp, SendGrid, and ActiveCampaign automatically rewrite links with their own reputable tracking domains to provide analytics. This practice is considered safe because these domains are actively managed for deliverability and are trusted by major mailbox providers, unlike the less controlled, generic shorteners that often trigger spam filters.
Key findings
- Generic Shorteners Risk: Using generic public link shorteners like Bitly or TinyURL in emails can severely harm deliverability, as these services are frequently exploited by spammers, leading to association with malicious content and increased likelihood of being flagged as spam.
- ESP Tracking Safety: Email Service Providers (ESPs) utilize their own proprietary tracking domains to rewrite links for click tracking, a standard and safe practice that does not negatively impact deliverability.
- Reputation Management: The domains used by ESPs for click tracking are actively managed and monitored for reputation, ensuring they are trusted by mailbox providers and spam filters, in stark contrast to the often blacklisted domains of generic shorteners.
Key considerations
- Avoid Public Shorteners: Always avoid incorporating generic public URL shorteners directly into your email content, especially for transactional or marketing messages, to prevent deliverability issues.
- Embrace ESP Tracking: Leverage your Email Service Provider's built-in click tracking functionality, as this system is designed for deliverability and provides valuable analytics without risking your sender reputation.
- Custom Tracking Domains: If your ESP offers the option, consider setting up a custom tracking domain for your links. This enhances branding and provides greater control over your link reputation, further improving deliverability.
What email marketers say
15 marketer opinions
The impact of link shorteners on email deliverability largely depends on the type of shortener used. Generic public services, such as Bitly or TinyURL, are widely advised against because their domains are frequently abused by spammers. This can lead to these links being flagged as suspicious by spam filters, negatively affecting your sender reputation and increasing the likelihood of your emails landing in the spam folder or being blocked entirely. In contrast, Email Service Providers (ESPs) typically use their own proprietary, carefully managed domains for click tracking. This process, while also involving a redirect, is considered a standard and safe practice because ESPs actively maintain the reputation of these domains, ensuring they are trusted by mailbox providers and do not harm deliverability. Marketers are strongly encouraged to leverage their ESP's native click tracking functionality or to set up custom tracking domains for improved brand trust and inbox placement.
Key opinions
- Public Shorteners are Risky: Generic public link shorteners are widely considered problematic for email deliverability because they obscure the final destination of a link, a behavior often associated with malicious content, leading to negative scores from spam filters and increased blacklisting.
- ESP Tracking is Safe: Email Service Providers' (ESPs) built-in click tracking mechanisms are generally safe and do not negatively impact deliverability. They work by wrapping links with their own carefully managed and reputable domains, which are trusted by mailbox providers.
- Reputation is Key: The core issue isn't link shortening itself, but the reputation of the domain used. Public shorteners often have poor reputations due to widespread abuse by spammers, while ESP-managed tracking domains are actively monitored and maintained to ensure good deliverability.
- Double Redirects: Some public link shorteners or complex tracking setups can create double-redirects, which may trigger browser security errors for recipients, diminishing trust and user experience.
Key considerations
- Prioritize ESP Tracking: Always rely on your Email Service Provider's (ESP) native click tracking feature for links within your emails. These systems are designed to maintain good sender reputation and deliverability.
- Avoid Generic Shorteners: Steer clear of third-party public link shorteners like Bitly or TinyURL for all email communications, as their frequent misuse by spammers can significantly damage your deliverability and lead to blocks.
- Consider Custom Domains: If your ESP offers the option, implement a custom tracking domain. This provides a branded, trusted link experience that further enhances your email's credibility with spam filters and recipients.
- Review Plain-Text Defaults: Be aware that some ESPs, like Mailchimp, might not add click-tracking redirects to plain-text emails by default, displaying raw links instead. Verify your ESP's behavior for plain-text versions.
Marketer view
Marketer from Email Geeks explains that public link shorteners are problematic because they can obscure malicious links, leading to negative scores from spam filters, with the reputation issue specific to the shortener used. She also notes that double-redirects can cause browsers to display security errors.
11 Nov 2022 - Email Geeks
Marketer view
Marketer from Email Geeks explains that link shorteners themselves aren't the issue, but rather public link shorteners used for obfuscation, such as bit.ly, are the concern for email deliverability.
21 Jan 2025 - Email Geeks
What the experts say
3 expert opinions
The question of whether link shorteners impact email deliverability, particularly with ESP click tracking, has a clear distinction: generic shorteners are a risk, but ESPs' built-in tracking systems are not. Email Service Providers (ESPs) commonly utilize their own sophisticated click tracking mechanisms that rewrite the original destination URL with a tracking domain. This process, while effectively 'shortening' or obscuring the original link, is distinct from using public link shorteners. Experts confirm that ESPs' internal click tracking generally does not negatively affect deliverability. This is primarily because ESPs control and diligently manage the reputation of their tracking domains, ensuring they are trusted by mailbox providers, unlike the frequently abused domains of many third-party shortening services.
Key opinions
- ESP Link Obscuration: Many Email Service Providers (ESPs) routinely obscure or rewrite destination URLs with their own tracking domains and parameters as part of their click tracking process.
- Generic Shorteners Harmful: Generic link shorteners can negatively impact email deliverability because they are often used by spammers, leading their domains to be frequently blacklisted by mailbox providers.
- ESP Tracking is Safe: Despite also modifying links, Email Service Providers' (ESPs) own click tracking systems typically do not negatively affect email deliverability.
- Reputation Management is Key: The primary reason ESP click tracking is considered safe is that ESPs actively manage and maintain the reputation of their proprietary tracking domains, ensuring they are trusted by mailbox providers and do not trigger spam filters.
Key considerations
- Differentiate Shorteners: It is crucial to understand the distinction between generic, public URL shorteners and the proprietary click tracking systems employed by Email Service Providers; they operate differently regarding deliverability.
- Trust ESP Systems: Always leverage your Email Service Provider's built-in click tracking functionality, as these systems are engineered to maintain high deliverability and manage the reputation of their tracking domains.
- Avoid Generic Tools: Completely avoid using third-party, generic link shortening services for any links within your email campaigns, as their domains are frequently associated with spam and can severely harm your sender reputation.
Expert view
Expert from Email Geeks clarifies that at many ESPs, link tracking does indeed obscure the destination URL by replacing it with a tracking domain and parameters.
17 Apr 2024 - Email Geeks
Expert view
Expert from Spam Resource explains that while generic link shorteners can be problematic for email deliverability due to their frequent use by spammers, Email Service Providers' (ESPs) own click tracking systems typically do not negatively impact deliverability. ESPs use their own domains for tracking links, and because they actively manage the reputation of these domains, they are generally considered safe by mailbox providers, unlike many third-party link shortening services.
2 Apr 2024 - Spam Resource
What the documentation says
4 technical articles
Major Email Service Providers (ESPs) and leading mailbox providers consistently confirm that while generic link shorteners can harm deliverability, an ESP's own click tracking mechanisms are generally safe and even beneficial. ESPs like SendGrid and Mailchimp automatically rewrite all links with their proprietary tracking domains for analytics purposes. This practice does not negatively impact email deliverability because these ESPs actively manage and maintain the strong reputation of their tracking domains, ensuring they are trusted by mailbox providers. In contrast, using external, generic link shorteners is strongly discouraged. Mailbox providers, including Google and Microsoft, view these third-party shorteners with suspicion due to their frequent association with spam and malicious content, potentially causing deliverability issues.
Key findings
- ESP Link Rewriting: Leading Email Service Providers such as SendGrid and Mailchimp automatically rewrite original URLs with their own tracking domains to enable click tracking.
- Managed Domain Reputation: ESPs diligently manage the reputation of their proprietary tracking domains, ensuring they are trusted by major mailbox providers and do not negatively impact deliverability.
- Deliverability Safety of ESP Tracking: This standard ESP practice of wrapping links for click tracking is widely considered safe for deliverability because the associated domains are actively monitored and maintained for trustworthiness.
- Generic Shorteners' Risk: Using external, generic link shorteners can significantly harm deliverability, as these domains are often associated with suspicious activity, making it difficult for recipient mail servers and spam filters to trust the link's destination.
- Mailbox Provider Scrutiny: Services like Microsoft's Exchange Online Protection (EOP) and Defender for Office 365 are designed to scan and trust legitimate ESP-wrapped links, while showing suspicion towards untracked or generically shortened links that could conceal malicious content.
Key considerations
- Prioritize ESP Tracking: Always leverage your Email Service Provider's (ESP) native click tracking functionality, as these systems are designed for optimal deliverability and provide valuable analytics without risking your sender reputation.
- Avoid Generic Shorteners: Never use generic, third-party link shorteners like Bitly or TinyURL within your email content, as their association with spam can severely damage your deliverability and lead to emails being blocked.
- Understand Trust Mechanisms: Recognize that major mailbox providers like Google and Microsoft prioritize the reputation of the link's domain; legitimate ESP-wrapped links are trusted, while untracked or generic shortened links are viewed with suspicion.
Technical article
Documentation from SendGrid explains that they automatically rewrite all links in emails to their own tracking domain (e.g., u[numbers].sgiz.net) for click tracking purposes. This standard ESP practice provides analytics and implicitly ensures deliverability, as SendGrid carefully manages the reputation of these domains, differentiating them from potentially harmful generic shorteners.
25 Aug 2024 - SendGrid
Technical article
Documentation from Mailchimp details that they track clicks by replacing original URLs with Mailchimp tracking URLs. They explicitly state that enabling this click tracking, which involves link rewriting, is generally safe for deliverability because Mailchimp actively manages the reputation of its tracking domains, implicitly advising against using third-party shorteners within email content.
14 Apr 2023 - Mailchimp
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