How do link redirects affect email reputation and deliverability?

Key findings

• ISP behavior: Major inbox providers consistently follow link redirects to assess the final destination.
• Security scan: This is primarily to ensure the landing page does not pose a security or fraud risk to recipients.
• Reputation impact: The reputation of the ultimate landing page domain can indeed influence how an email is treated by spam filters.
• Normal redirects: Simple redirects for click-tracking are generally not a problem unless other suspicious elements are present in the email or sending behavior.

Key considerations

• Avoid stealth redirects: Attempting to hide the final destination of a link is a significant red flag and can lead to immediate blocking by most providers. Such practices are typically flagged as malicious.
• Limit redirect chains: While one or two redirects are usually acceptable, excessive redirect chains (e.g., four or five) can trigger spam filters and negatively impact deliverability.
• Domain reputation: The reputation of every domain involved in the redirect chain (including the ESP's tracking domain and the final landing page domain) is critical. A poor reputation on any of these can harm deliverability. Read more about how external domains affect sender reputation.
• Suspicion triggers: Redirects are more likely to be flagged by spam filters if the email otherwise exhibits suspicious characteristics or bad sending practices.

Key opinions

• Recipient trust: A 'suspicious link' warning, often triggered by problematic redirects or link shorteners, significantly erodes recipient trust, even if the email lands in the inbox. This can lead to lower engagement and increased spam complaints.
• Direct linking preference: Many marketers opt to link directly to their final landing pages to avoid potential deliverability and trust issues associated with redirects.
• ESP tracking links: Redirects generated by ESPs for click tracking are generally considered acceptable, provided the ESP's tracking domain maintains a good sending reputation. For more details, see our article on how link shorteners impact deliverability with ESP click tracking.
• Generic shorteners: General (free) link shorteners like bit.ly are often flagged as suspicious due to their frequent use in malicious campaigns.

Key considerations

• Custom shortener domains: If using a link shortener is necessary, it is highly recommended to use a custom domain unique to your brand instead of a generic, communal one.
• Even legitimate redirects can flag: Problems can arise even with redirects between two seemingly legitimate, different domains, emphasizing the need for careful monitoring. This is also covered in our article how a sending domain that redirects affects deliverability.
• Complexity in troubleshooting: Pinpointing the exact cause of a deliverability issue stemming from a redirect can be time-consuming, making simplified linking a practical solution.
• Practicality vs. deliverability: While direct links minimize risk, practical considerations such as web server load, advanced click tracking, and e-commerce software limitations often necessitate the use of redirects.

Key opinions

• Link following for security: Inbox providers (ISPs) actively follow links to ensure the final destination poses no security or fraud risk to recipients, indicating thorough vetting of all linked content.
• Website reputation affects email reputation: The reputation of a website, including its Google ranking, can directly influence the associated email domain's reputation, especially for major providers like Google.
• Conditional redirect checking: While ISPs don't always follow every redirect, they are more likely to inspect click-throughs when the email exhibits suspicious characteristics, such as signs of 'snowshoe spamming' or other abuse patterns.
• Normal redirects are acceptable: A single, standard redirect, such as those used for legitimate click tracking, is generally not problematic in itself and will not inherently affect deliverability with large providers.

Key considerations

• Prohibit stealth redirects: Any attempt to conceal the final content or destination through redirection is strongly discouraged and is often blocked outright by email providers due to security concerns.
• Multiple redirects are problematic: While one or two redirects might pass unnoticed, a higher number, such as four or five, can be a clear indicator of suspicious activity and may lead to deliverability issues.
• Reputation of redirecting domains: The reputation of all domains involved in the redirection process is crucial. If any intermediate or final domain has a poor reputation, it will negatively impact email deliverability. This is related to tracking URL subdomain alignment.
• Pragmatic removal: If a specific redirect is causing deliverability problems and the exact cause is difficult to diagnose, the most prudent course of action is often to remove the redirect entirely. This removes a lot of potential problems, though it isn't always practical due to other system requirements.

Key findings

• Comprehensive link evaluation: Email filtering systems perform deep scans of all URLs within an email, including those involved in redirects, to detect potential threats.
• Destination reputation is key: The reputation of the final landing page domain is a significant factor in determining an email's trustworthiness and deliverability. If the final destination is on a blocklist or has a poor reputation, the email is likely to be flagged.
• Transparency is mandated: Official guidelines often prohibit deceptive or obfuscated linking practices, as these are common tactics used by spammers and phishers.
• Consistent URL reputation: All URLs encountered during a redirect chain contribute to the overall reputation assessment of the email message.

Key considerations

• Maintain domain alignment: For tracking links, ensuring that the tracking subdomain aligns with the primary sending domain can significantly enhance trust signals and improve deliverability. See our guide on does tracking URL subdomain alignment affect email deliverability.
• Minimize redirect hops: While technical documentation may not specify an exact number, the general consensus is to minimize the number of redirects in a chain to reduce complexity and potential filtering triggers. Our resource on how do multiple or long links affect email deliverability provides further insight.
• Use secure protocols: All links and redirect paths should utilize HTTPS to ensure data encryption and reinforce security, which is a strong positive signal for ISPs.
• Content at destination matters: The quality and nature of the content on the final landing page are paramount. If the destination content is deemed spammy, malicious, or deceptive, it will negatively impact the sender's reputation, regardless of the redirect structure.