How do multiple or long links affect email deliverability?
Matthew Whittaker
Co-founder & CTO, Suped
Published 10 May 2025
Updated 19 Aug 2025
8 min read
Email deliverability is a complex dance, with many factors influencing whether your messages land in the inbox or the spam folder. One area that often raises questions, and for good reason, is the impact of links. Many marketers and email senders find themselves wondering just how many links are too many, or if a very long URL could be causing problems.
It's a common misconception that links are inherently bad for deliverability. The truth is more nuanced. Email service providers (ESPs) and spam filters analyze links as part of their assessment of an email's legitimacy, but it is not just the presence of links that matters, rather it is their quantity, quality, and the way they are presented.
In this guide, I will explore how the number and length of links can affect your email deliverability, and what steps you can take to ensure your linked content helps, rather than harms, your inbox placement.
Multiple links and their impact
The number of links in an email can certainly influence its deliverability. While there is no hard and fast rule for an exact number that triggers spam filters, a disproportionately high count, especially in plain-text or cold emails, can raise red flags. Spam filters often use heuristics to identify patterns common in unsolicited bulk email, and an abundance of links is one such pattern.
Consider the context of your email. A newsletter with multiple articles linked may be perfectly acceptable, whereas a cold outreach email with ten different links will likely face scrutiny. This is particularly true if the links point to a variety of external or unfamiliar domains.
When filters detect an unusually high number of links, they might assume the email is trying to funnel recipients to multiple malicious sites or is simply a generic, untargeted message. This can lead to your email being flagged as spam or even blocked. It's important to ask yourself, how many links in an email are too many, and simplify where possible.
Too many links
Adding links to cold emails can negatively affect deliverability. Each additional link adds another data point for spam filters to analyze, increasing the chances of hitting a trigger.
Long URLs and shorteners
The length of your URLs also plays a role. While modern email clients and web browsers handle long URLs gracefully, excessively long links can sometimes appear suspicious to spam filters. This is especially true if they contain many parameters, random characters, or look deliberately obfuscated.
Long links are often associated with tracking parameters, which are common in legitimate marketing emails. However, if these tracking links are poorly configured, or if the domain they point to has a questionable reputation, it can lead to deliverability issues. This is why some senders ask, do long URLs affect email spam filtering?
Another concern is the use of URL shorteners, particularly generic ones like Bitly. While convenient, these services can be abused by spammers, leading to a poorer reputation for the shortened domain. If a shortener's domain is on a public blacklist (or blocklist), or if it has been used for phishing, emails containing links from that shortener will almost certainly be flagged. This is why it's crucial to understand how URL shorteners and domain reputation impact email deliverability.
Long links in emails
Long URLs can appear suspicious to spam filters, especially if they are heavily laden with tracking parameters or seem obfuscated. This concern is often amplified when generic URL shorteners are used, as these can be associated with spam activities.
Consider using clear, concise links that are directly relevant to your content. If tracking is necessary, ensure your tracking domains are reputable and that the full URL, including parameters, does not look overly complex or suspicious. Monospace formatting is not for links. Example: www.example.com/product?id=123&utm_source=email
Domain reputation and link quality
Beyond quantity and length, the reputation of the domain you are linking to is paramount. If you link to a domain with a poor sender reputation, or one that is frequently associated with spam or malicious activity, it can severely impact your own deliverability, regardless of how few or how short your links are. This includes third-party links or any content not hosted on your primary domain. You can learn more about this by checking how link redirects affect email reputation and deliverability.
Spam filters don't just look at the URL itself, but also at the domain's history, its presence on blacklists (or blocklists), and its overall trustworthiness. Linking to compromised websites or those known for malware can instantly land your email in the spam folder. Conversely, linking to reputable, well-known sites can build trust with ESPs.
It's also worth noting the type of link. Hyperlinks embedded in descriptive text (read more here) are generally preferred over raw, exposed URLs. Descriptive link text provides context and improves user experience, signaling to filters that the link is legitimate and intended for user interaction, rather than a suspicious redirection. Think about how HTTP tracking links affect deliverability.
Bad link practices
Over-linking: Including too many links, especially in short emails, can make your message look like spam.
Suspicious domains: Linking to domains with poor reputation or those on a blocklist.
Generic shorteners: Using common URL shorteners that have been abused by spammers. Avoid Bitly links if possible.
Good link practices
Relevance: Only include links that are essential and provide value to the recipient.
Reputable domains: Link only to trusted domains with strong reputations.
Branded shorteners: If using shorteners, opt for custom, branded ones to maintain control and reputation.
Balancing content and engagement
While minimizing links and keeping them concise is good practice, it is equally important to ensure your email content maintains a natural appearance. An email with too many links and no images may also trigger spam filters, particularly if combined with existing domain or IP reputation issues.
The key is to strike a balance. Don't remove valuable links just to reduce the count if they serve a genuine purpose for your recipient. Instead, focus on structuring your email content to naturally integrate links where they are most helpful and expected. This means clear calls to action, relevant resources, and sensible navigation within your email.
Email service providers (ESPs) prioritize user engagement. If your emails consistently receive clicks on links, it signals to ESPs that your content is valuable and relevant, which can boost your sender reputation. Conversely, emails with links that are never clicked can be seen as less engaging, potentially leading to lower inbox placement over time. This underscores the importance of sending emails that resonate with your audience.
Link placement: Strategically place links where they make sense contextually, rather than just scattering them throughout the email. Key calls to action should be prominent, but not overwhelming.
Clear anchor text: Use descriptive and relevant anchor text for your links. Avoid generic phrases like 'click here' when possible. This helps both users and spam filters understand the link's purpose.
Mobile optimization: Ensure your links are easily tappable on mobile devices. Cluttered links can lead to accidental clicks and a poor user experience, which can indirectly impact engagement metrics.
Mitigation and best practices
Ultimately, the goal is to send emails that are both effective and deliverable. This means being mindful of how your links are perceived by spam filters, while still providing a valuable experience for your recipients. Regularly monitoring your deliverability metrics and keeping an eye on your sender reputation can help you identify if links are becoming an issue. If you're encountering deliverability challenges, consider reviewing your link strategy as part of a broader audit.
A good practice is to implement robust email authentication protocols such as SPF, DKIM, and DMARC. These measures help verify that your emails are legitimate and reduce the likelihood of them being flagged as spam, even if they contain multiple or slightly longer links. A strong authentication setup provides a foundational layer of trust. You can learn more about a simple guide to DMARC, SPF, and DKIM.
Remember, email deliverability is an ongoing effort. By adhering to best practices for link usage, maintaining a healthy sender reputation, and employing proper authentication, you can significantly improve your chances of reaching the inbox consistently.
Views from the trenches
Best practices
Keep the number of links to a minimum, focusing on essential calls to action and relevant resources.
Use descriptive anchor text for your links, providing clear context to both recipients and spam filters.
Prioritize linking to reputable domains with strong sender reputations, avoiding unknown or suspicious URLs.
If using URL shorteners, opt for custom, branded short domains to maintain better control over your link reputation.
Common pitfalls
Including a large number of links, especially in cold emails or plain-text messages.
Using generic URL shorteners that have been previously associated with spam or malicious activity.
Linking to domains with poor sender reputation or those listed on public blacklists (or blocklists).
Employing excessively long or obfuscated URLs that look suspicious to automated filters.
Expert tips
Monitor your sender reputation regularly to identify any negative impacts from your link strategy.
Test your emails with various link configurations using an email deliverability tester to see how they perform.
Ensure all your email authentication protocols like SPF, DKIM, and DMARC are correctly configured.
Segment your audience and tailor your link strategy based on their engagement history and preferences.
Marketer view
Marketer from Email Geeks says they have seen anecdotal evidence of multiple links affecting deliverability, indicating it is a real concern in the field.
2020-01-10 - Email Geeks
Expert view
Expert from Email Geeks says the reputation associated with included links may be impacting deliverability, and having more links increases the risk of including URLs with less-than-ideal reputations.
2020-01-11 - Email Geeks
Key takeaways for link optimization
The impact of multiple or long links on email deliverability is not a simple 'yes' or 'no' answer, but rather a complex interplay of quantity, length, domain reputation, and overall email content. While a high number of links or excessively long URLs can raise suspicions with spam filters, the context and quality of these links are equally, if not more, important.
By adopting a strategic approach to link usage, prioritizing relevance and user experience, and ensuring the reputation of all linked domains, you can navigate these challenges effectively. Focus on delivering value through your content and ensuring all elements, including links, contribute to a trustworthy and engaging email experience. This proactive stance will significantly contribute to your long-term email deliverability success.
