Do different TLDs affect cold email deliverability?
Michael Ko
Co-founder & CEO, Suped
Published 17 Apr 2025
Updated 16 Aug 2025
8 min read
When delving into the world of cold email outreach, a question that frequently surfaces is whether the top-level domain (TLD) you choose impacts your deliverability. It's a nuanced topic, and while the TLD certainly plays a role, it's often not the sole determinant of success or failure. My goal here is to clarify how different TLDs are perceived and to offer a comprehensive understanding of their effect on your cold email campaigns.
The internet's landscape has expanded dramatically beyond the familiar .com or .org, introducing a multitude of new generic TLDs (gTLDs) like .xyz, .tech, and .app. Each TLD carries a certain reputation, built over time through its usage patterns. This reputation can influence how internet service providers (ISPs) and spam filters assess your emails.
While some might argue that TLDs are a minor factor, I've seen firsthand how an unsuspecting choice can lead to significant deliverability hurdles. Understanding these underlying mechanisms is crucial for anyone aiming to land their messages in the inbox rather than the spam folder.
The role of TLDs in sender reputation
ISPs and email providers constantly monitor sending patterns and reputations associated with different TLDs. A TLD with a history of high spam rates or malicious activity will naturally be viewed with more suspicion. This isn't an arbitrary judgment, but rather a protective measure to safeguard their users from unwanted or harmful content.
Common TLDs, particularly .com, have generally established a strong, positive reputation due to their widespread and legitimate use. When you send from a .com domain, you often inherit a baseline level of trust. This is why many recommend sticking to .com for cold outreach campaigns whenever possible, as it is often considered the best domain extension for cold email.
Conversely, some newer or less common TLDs may not have had enough time to build a robust positive reputation, or they might have been heavily adopted by spammers. This can lead to increased scrutiny for emails originating from these domains, potentially resulting in higher rates of emails landing in spam folders or being blocklisted (also known as blacklisted).
This doesn't mean all alternative TLDs are inherently bad, but rather that some carry a higher risk profile than others. It's about how ISPs assess sender reputation, which is influenced by numerous factors, including the TLD.
Understanding TLD reputation
Different TLDs inherently carry varying levels of trust. Established TLDs like .com, .org, and .net are generally seen as more credible due to their long history of legitimate use. Newer or less regulated TLDs might have a higher association with spam or marketing, making them riskier for cold outreach.
ISPs monitor sending patterns and complaints associated with specific TLDs. If a TLD has a disproportionately high volume of spam or user complaints, it's flagged as potentially risky. This can lead to stricter filtering for all mail from that TLD, regardless of individual sender reputation.
The inherent challenge of cold email
It's important to understand that the TLD is just one piece of a much larger puzzle. The fundamental challenge with cold email is that, by definition, it's unsolicited. This means recipients haven't opted in to receive your messages, which can lead to higher spam complaint rates, regardless of your chosen TLD.
Spam filters are sophisticated. They analyze numerous signals, including sender reputation, email content, engagement metrics, and historical sending behavior. A pristine .com domain won't magically make your cold emails land in the inbox if your content is generic, your list is unsegmented, or recipients consistently mark your emails as spam. The content of your cold email itself is paramount.
In fact, I've observed that the impact of the cold email tactic itself often dwarfs the influence of the TLD. If you're sending high volumes of unsolicited mail, you're already operating in a high-risk zone for deliverability. This can lead to your domain (and even your IP address) being added to blocklists (or blacklists), which is a far more severe problem than a questionable TLD.
Even with the best intentions, such as raising money for charities, unsolicited emails fall under the category of spam from a technical and regulatory standpoint. This often leads to email providers blocking such messages because they violate terms of service, regardless of the TLD used.
Cold email
Unsolicited emails carry inherent deliverability risks due to user complaints and automated spam filters. The primary challenge isn't the TLD, but the nature of the outreach itself. A negative reputation from cold emailing can impact your entire domain, including warm email campaigns.
Reputation damage: High spam complaint rates can quickly degrade your domain's sender reputation.
Spam folder placement: Even with a good TLD, cold emails often land in spam or junk folders.
Blocklisting risk: Aggressive cold emailing can lead to your domain or IP being put on a blacklist.
Permission-based email
Building an engaged, opt-in list is the cornerstone of excellent email deliverability. When recipients expect and want your emails, engagement metrics improve, leading to better inbox placement and a stronger sender reputation. This approach minimizes TLD-related concerns.
High engagement: Opt-in lists lead to higher opens, clicks, and fewer complaints.
Inbox placement: ISPs favor domains with consistent positive engagement.
Lower blocklisting risk: Domains with good practices are less likely to be blocklisted.
Strategies for managing TLD impact
Given the potential impact of TLDs, especially for cold outreach, what steps can you take to minimize risk and improve your chances of reaching the inbox? One common strategy is to use a separate domain for cold email campaigns, distinct from your primary domain. This isolates any potential negative impact and protects your main brand identity.
If you choose to use alternative TLDs for cold email, it's advisable to select those that have a relatively neutral or positive reputation. While some TLDs might trigger spam filters, others, such as .co, are often used for legitimate business purposes and may carry less risk than, say, .xyz or .info. You can also explore the impact of new or uncommon domain extensions.
Furthermore, any new domain, regardless of its TLD, starts with a zero reputation. It's essential to properly warm up any new domain before sending high volumes of cold emails. This involves gradually increasing your sending volume over time to build a positive sending history with ISPs. Without proper warming, even a .com domain can struggle to reach the inbox.
Remember, the goal is to build and maintain a strong email domain reputation. This is achieved through consistent, legitimate sending practices, low complaint rates, and high engagement, regardless of your TLD choice. Some reports even highlight specific domains to avoid if you are conducting cold email outreach.
TLD Category
Characteristics
Cold Email Risk
Established TLDs (.com, .org, .net)
High trust, widely recognized for legitimate use, broad adoption.
Lower inherent risk, but still highly dependent on sending practices.
Country Code TLDs (ccTLDs like .co, .io, .ca)
Varying trust levels; some are popular for startups or tech. Can be location-specific.
Moderate risk; depends on the specific ccTLD's reputation and target audience.
New gTLDs (.xyz, .online, .tech, .info)
Newer, less established, some have higher association with spam or marketing.
Higher risk; often subjected to stricter filtering until a positive reputation is built.
Authentication and its paramount importance
Regardless of the TLD you choose, robust email authentication is non-negotiable for deliverability. SPF, DKIM, and DMARC are crucial protocols that verify your sending identity and protect your domain from spoofing and phishing attempts. Implementing these correctly signals to ISPs that your emails are legitimate and that you're a responsible sender.
When SPF (Sender Policy Framework) is properly configured, it tells receiving mail servers which IP addresses are authorized to send email on behalf of your domain. DKIM (DomainKeys Identified Mail) adds a digital signature to your outgoing emails, allowing recipients to verify that the email hasn't been tampered with in transit. DMARC (Domain-based Message Authentication, Reporting, and Conformance) builds on these by allowing you to specify how receiving servers should handle emails that fail SPF or DKIM checks, and it provides reporting to monitor your email streams.
These authentication methods provide a strong signal of legitimacy, often overriding some of the inherent TLD reputation concerns. An email from a less common TLD with perfect SPF, DKIM, and DMARC alignment will likely perform better than an email from a .com domain with missing or misconfigured authentication.
I always recommend ensuring these records are correctly set up and monitored. It's a foundational step for any email program, especially for cold outreach where you're already fighting an uphill battle for inbox placement.
Setting up your DMARC record
A basic DMARC record is a TXT record added to your DNS. Here’s an example:
This record tells receiving servers that you use DMARC, what policy to apply (in this case, p=none for monitoring), and where to send aggregate reports. For a deeper dive, read our article on a simple guide to DMARC, SPF, and DKIM.
Views from the trenches
Best practices
Always warm up new domains before sending high volumes of cold emails to build a positive reputation.
Utilize email authentication protocols like SPF, DKIM, and DMARC to prove your legitimacy and improve trust.
Consider using a dedicated domain for cold email to protect the reputation of your primary business domain.
Focus on highly targeted, personalized content to reduce spam complaints and improve engagement.
Common pitfalls
Using new or obscure TLDs without proper warming and authentication can lead to immediate spam folder placement.
Neglecting email authentication or having misconfigured records will severely hurt deliverability, regardless of TLD.
Sending high volumes of unsegmented or generic cold emails, even from a .com, will quickly damage your sender reputation.
Failing to monitor blocklists (blacklists) can mean you miss critical deliverability issues from TLD-related flags.
Expert tips
Regularly monitor your domain's reputation using tools like Google Postmaster Tools.
Maintain low bounce rates by regularly cleaning your email lists.
Encourage engagement by providing clear value in your cold emails.
Stay informed about ISP policy changes that might affect TLD perception.
Marketer view
Marketer from Email Geeks says that the choice of TLD for cold emails doesn't significantly change deliverability outcomes compared to the act of cold emailing itself.
2022-10-01 - Email Geeks
Expert view
Expert from Email Geeks says that sending unsolicited email, regardless of its purpose (even charity), is considered spam and violates email provider terms of service.
2022-10-01 - Email Geeks
Final thoughts on TLDs and cold email
To summarize, different TLDs can indeed affect cold email deliverability, primarily because of how ISPs perceive their historical reputation. Established TLDs like .com often carry more inherent trust, while newer or less common TLDs might face higher scrutiny. However, this is just one factor among many.
The most significant influence on your cold email deliverability will always be your sending practices. Unsolicited emails, by their nature, are prone to higher spam complaints. Therefore, focusing on list quality, personalization, engagement, and robust email authentication (SPF, DKIM, DMARC) will yield far greater improvements than simply choosing a specific TLD.
For optimal results, I recommend using a dedicated domain for cold outreach, warming it up properly, and ensuring all your authentication records are impeccable. While the .com TLD remains a strong choice for its established reputation, a well-managed sending strategy can mitigate many of the risks associated with other TLDs.
