Do new or uncommon domain extensions (.club, .online, .tech, .app) affect email deliverability?
Michael Ko
Co-founder & CEO, Suped
Published 9 Jul 2025
Updated 16 Aug 2025
7 min read
When choosing a domain name, the focus often lies on branding and memorability. However, for email marketers and businesses, the chosen domain extension, also known as a Top-Level Domain (TLD), carries significant implications for email deliverability. With the proliferation of new and uncommon domain extensions like .club, .online, .tech, and .app, a crucial question arises: do these newer TLDs affect whether your emails reach the inbox?
The short answer is yes, they can. While a TLD isn't the sole determinant of your email's fate, it plays a role in how internet service providers (ISPs) and spam filters perceive your sending domain. Historically, traditional TLDs like .com, .org, and .net have built a stronger reputation due to their long-standing presence and widespread legitimate use. Newer gTLDs (generic Top-Level Domains), on the other hand, often start with a clean slate but can quickly accumulate negative associations if abused by spammers.
This perception gap can lead to deliverability challenges, making it harder for emails from less common TLDs to bypass spam filters and land in the primary inbox. It's a complex interplay of domain reputation, sender behavior, and the filtering algorithms of major mail providers.
The reputation challenge of new TLDs
One of the primary reasons why new or uncommon domain extensions might struggle with email deliverability is their susceptibility to abuse. Because they are often cheaper or easier to acquire in bulk, these TLDs can become favored by spammers and malicious actors. When a TLD becomes associated with a high volume of unsolicited or fraudulent emails, it builds a poor reputation, leading to stricter filtering by ISPs.
For instance, statistics show that certain newer gTLDs have alarmingly high percentages of spammy domains. These figures paint a clear picture of the inherent risk associated with choosing such extensions for legitimate email sending. The high prevalence of abuse means that even a well-intentioned sender might face an uphill battle to establish trust with email providers.
While abuse certainly occurs across all TLDs, including popular ones like .com, the sheer percentage of illegitimate usage on some new extensions makes them particularly challenging. This is not necessarily due to a flaw in the TLD itself, but rather how it is exploited. You can check the general abuse levels of different TLDs to see how they compare and inform your decision.
Domain Extension
Percentage of Spammy Domains
.club
97%
.online
92%
.tech
92%
.app
79%
.io
13% (all time), 56% (newly seen)
This data suggests that domains using these TLDs are significantly more likely to be involved in spam activities, which contributes to a general negative perception by mail servers. For more detailed statistics on TLD abuse, you can review data from organizations like Spamhaus.org on TLD abuse levels.
Understanding the mechanisms of TLD filtering
It's important to understand that while a TLD's general reputation is a factor, it is often not the sole or even primary reason for deliverability issues. ISPs and email filters employ complex algorithms that evaluate numerous signals to determine whether an email is legitimate or spam. These signals include your domain's sending history, IP address reputation, email authentication, content quality, and recipient engagement. For more on this, consider reading about how TLDs affect email deliverability.
A new domain, regardless of its TLD, inherently lacks a sending history, which can make it appear suspicious to filters. This is why a proper domain warm-up process is crucial for any new sending domain. Sending a large volume of emails from a brand-new domain can immediately trigger spam filters, irrespective of whether it's a .com or a .club.
Another critical aspect is the domain registrar and its policies. Some registrars that offer very cheap or bulk domain registrations for new gTLDs may inadvertently attract spammers, further tainting the reputation of those TLDs. A registrar with lax compliance against abuse contributes to a lower overall trust score for domains registered through them.
The bias against uncommon TLDs
Some ISPs and filtering companies confess to having a general bias, often blocking or applying higher scrutiny to what they perceive as "weird" TLDs. This isn't always based on hard data but rather a precautionary measure against known spam vectors. This is particularly true for country code TLDs (ccTLDs) like .us that aren't at the second level with a 2-character state code, which are generally considered quite suspect.
This bias, combined with high historical abuse rates, means that using a lesser-known TLD can start you off with a disadvantage, requiring more diligent efforts to prove your legitimacy.
Building trust regardless of your TLD
If you're already using a newer or uncommon TLD, or if it's your best option, all hope is not lost. The key is to compensate for any inherent TLD-related skepticism with impeccable sending practices. This means prioritizing every other aspect of email deliverability to build and maintain a strong sender reputation, regardless of your domain extension. For comprehensive guidance, explore our expert guide to improve email deliverability.
Establishing proper email authentication, such as SPF, DKIM, and DMARC, is non-negotiable. These protocols verify that your emails are legitimately sent from your domain and haven't been tampered with. Without them, your emails are much more likely to be flagged as suspicious, regardless of your TLD. You can learn more in our simple guide to DMARC, SPF, and DKIM.
Maintaining a clean email list and sending relevant, engaging content are equally important. High bounce rates, spam complaints, and low engagement signals can quickly tank your domain reputation, overshadowing any TLD-specific concerns. Monitoring your domain's reputation via tools like Google Postmaster Tools is essential.
Common TLDs (.com, .org, .net)
Initial perception: Generally trusted by ISPs due to long history and widespread legitimate use.
Reputation building: Easier to establish positive sender reputation; less initial skepticism.
Abuse rates: While present, typically lower percentages of spam relative to total usage compared to newer gTLDs.
Deliverability: Often a smoother path to inbox placement, assuming good sending practices.
New/Uncommon TLDs (.club, .online, .tech, .app)
Initial perception: May face immediate skepticism or be subject to stricter filtering rules.
Reputation building: Requires more effort and consistent positive sending behavior to overcome initial bias.
Abuse rates: Often significantly higher percentages of spam, making them prone to blocklisting (or blacklisting).
Deliverability: Can be more challenging, potentially leading to lower inbox placement rates if not managed meticulously.
Even with optimal setup, some TLDs might carry a stigma. For instance, some subdomains offered by platforms using specific gTLDs (e.g., myspammy.app offering free subdomains) can be heavily abused, further impacting the reputation of the parent TLD. This can pose challenges when you are trying to boost your email deliverability rates.
The key takeaway is that your domain extension is a piece of the puzzle, but your overall sending practices, including list management, content quality, and proper authentication, weigh far more heavily in the long run. Focusing on these core principles will give you the best chance of inbox success, regardless of your TLD.
Views from the trenches
Best practices
Maintain impeccable sending hygiene, including proper authentication (SPF, DKIM, DMARC) and regularly cleaning your email lists.
Carefully warm up any new sending domain, regardless of its TLD, starting with low volumes and gradually increasing.
Focus on high engagement rates and low complaint rates to build positive sender reputation, mitigating TLD biases.
Monitor your domain’s reputation diligently using tools like Google Postmaster Tools and blocklist checking services.
Common pitfalls
Choosing an uncommon TLD solely for its novelty without understanding its potential historical abuse rates or current perception.
Failing to implement robust email authentication, which is even more crucial for less common domain extensions.
Sending high volumes of emails from a brand new domain with an uncommon TLD, triggering immediate spam filters.
Ignoring signs of low engagement or high bounce rates, which can quickly harm reputation for any domain.
Expert tips
If your client is already using an uncommon TLD and achieving some deliverability, ongoing issues are less likely due to the TLD itself and more due to overall sending practices.
The rapid increase in spam rates for newly seen domains across some gTLDs indicates that recent registrations might face tougher scrutiny.
Many email deliverability issues stem from general sender reputation, not solely the domain extension.
Prioritize sender best practices to overcome potential TLD biases if you must use a less common extension.
Expert view
Expert from Email Geeks says to check if Spamhaus considers a specific TLD as abusive, noting that .net and .co are generally fine, but .club and similar new gTLDs may raise concerns due to how easily they are abused by spammers.
2022-04-13 - Email Geeks
Marketer view
Marketer from Email Geeks says that some ISPs and filtering companies confess to blocking emails from "weird" TLDs, citing a significant bias against many commercial TLDs due to lack of effective compliance from their registrars, who often promote bulk domain sales.
2022-04-13 - Email Geeks
Your domain extension and email success
While new or uncommon domain extensions (.club, .online, .tech, .app) can indeed affect email deliverability due to their higher association with spam and the biases of some email providers, they are not insurmountable obstacles. The TLD is one factor among many that influence your sender reputation.
The most critical components of strong email deliverability remain consistent: adherence to email authentication standards (SPF, DKIM, DMARC), meticulous list hygiene, engaging content, and a thoughtful domain warm-up process for new sending infrastructure. By excelling in these areas, you can mitigate many of the potential deliverability drawbacks associated with your chosen TLD.
Ultimately, if you opt for a less common TLD, be prepared to be extra vigilant with your email sending practices. Your diligence in maintaining a pristine sender reputation will be your strongest defense against spam filters and your greatest asset in reaching your recipients' inboxes.
