Are there deliverability issues sending from new .us domains to Gmail?
Michael Ko
Co-founder & CEO, Suped
Published 13 Aug 2025
Updated 15 Aug 2025
7 min read
I often encounter questions about whether choosing a less common Top-Level Domain (TLD) like .us for sending emails can inherently lead to deliverability issues, especially when targeting gmail.com users. While common wisdom suggests the TLD itself isn't the primary factor, recent experiences and observations indicate that new .us domains might face specific hurdles, particularly with getting into the inbox.
The reality is that new domains, regardless of their extension, start with a neutral reputation. They haven't yet built up the trust needed with internet service providers (ISPs) like Google. This lack of a track record can make the initial sending phase, often referred to as 'warming up', challenging. When a new domain, especially one that isn't a traditional .com, starts sending email, ISPs are naturally cautious.
Domain reputation and new TLDs
Gmail primarily relies on a multifactorial identifier to determine email legitimacy and sender reputation. This means they consider a combination of factors, including the sending domain, the IP address it's sending from, and the authentication setup (SPF, DKIM, DMARC). It's not about a single factor, such as the TLD, that triggers a broad block.
However, while Gmail does not filter with broad brushes that target an entire TLD, anecdotal evidence and third-party data suggest that some less traditional TLDs might carry a higher association with spam or malicious activity. For example, some blocklists or blacklists might assign a higher 'badness' percentage to .us domains compared to .com or .net. While Google doesn't directly use these external rankings for its reputation, it highlights a perception within the email ecosystem. You can learn more about general domain reputation in our practical guide to understanding your email domain reputation.
The key challenge for new .us domains often lies in establishing initial trust. Unlike established .com domains that have a history of good sending practices, a new .us domain starts from scratch. This means that even with perfect email content and good sending habits, the domain's newness combined with any perceived historical patterns of its TLD can lead to deliverability headwinds.
It's important to remember that Gmail's filtering philosophy is not to block legitimate mail, especially from widely used TLDs like .us, which are also adopted by government and educational institutions. However, their systems are designed to err on the side of caution when a domain has no clear sending history, to protect users from potential spam or phishing.
Specific challenges with new .us domains and Gmail
What I've observed is that while existing senders using .us domains generally don't face issues, new .us domains undergoing a warming process sometimes struggle specifically with Gmail. Even with low volumes, like 150 Gmail addresses per day, some new .us domains have been automatically routed to spam or blocked outright.
A common symptom of this is receiving a bounce message indicating low sending domain reputation. For example, a bounce message might look like this:
Gmail Bounce Error Exampleplaintext
smtp;550 5.7.1 [%%%] Our system has detected that this message is likely suspicious due to the very low reputation of the sending domain. To best protect our users from spam, the message has been blocked. Please visit https://support.google.com/mail/answer/188131 for more information.
Understanding the block message
This specific message points directly to a low reputation of the sending domain, not necessarily the TLD itself being universally blacklisted. It suggests that Google's systems view the new .us domain as suspicious because it lacks a positive sending history. This can be a challenging situation because there may not be enough volume for Google Postmaster Tools to provide detailed data to diagnose the issue further.
The critical takeaway is that Gmail's machine learning algorithms need time to observe consistent, positive sending behavior from a new domain to build trust. If the initial sending patterns trigger a low-reputation flag, it can be difficult to overcome without a carefully adjusted strategy. We have a specific guide on how to resolve Gmail issues with a new domain that can provide more detailed steps.
Building trust and improving deliverability
To effectively mitigate these deliverability issues, especially for new .us domains targeting Gmail, a robust strategy focusing on authentication, gradual volume increases, and consistent monitoring is essential. Even if your content is perfect and IPs are warm, the newness of the domain, combined with its TLD, can trigger stricter scrutiny.
Implementing a thorough warm-up process is crucial. Instead of sending 150 emails per day to Gmail addresses immediately, it's better to start with much smaller batches. Gmail is particularly sensitive to rapid volume increases from new domains, which can be interpreted as spamming behavior. Gradually increasing your sending volume allows Google's systems to learn and trust your sending patterns. You can find more insights on why your emails are going to spam in our blog.
New domain warm-up: challenges
Initial mistrust: ISPs, including Gmail, are wary of new domains, especially those under 90 days old, as they lack a proven sending history.
Volume sensitivity: Sending too many emails too quickly from a new domain can trigger spam filters and lead to blocks.
Lack of data: Google Postmaster Tools might not provide sufficient data for very low volumes, making diagnosis difficult.
Typical domain warm-up
For standard domain extensions like .com or .net, a new domain warm-up typically involves a gradual increase in sending volume, focusing on engaged recipients. While challenging, the TLD itself usually doesn't add an extra layer of scrutiny.
New .us domain warm-up for Gmail
Slower increments: Consider sending even slower than usual, especially for initial volumes to Gmail. Start with batches of fewer than 20 emails per day to Gmail if facing immediate blocks.
Web presence and search reputation: Ensure your sending domain has a legitimate web presence and a good search engine reputation, as these can indirectly influence email deliverability. A strong web presence adds legitimacy to your new domain and can help build trust more quickly with ISPs.
Monitor closely: Use all available metrics, including bounce rates and engagement data, to adjust your sending strategy dynamically. Pay close attention to Gmail's new sender guidelines to ensure compliance.
Beyond the initial warm-up, ensuring robust email authentication (SPF, DKIM, DMARC) is paramount. Gmail and Yahoo have recently tightened their requirements, making authentication a critical factor for inbox placement. A strong authentication setup signals to receiving servers that your email is legitimate and authorized. We offer a simple guide to DMARC, SPF, and DKIM to help you configure these essential records.
Beyond the TLD: other contributing factors
It's important to understand that the TLD (.us in this case) isn't the sole arbiter of deliverability. Gmail's filtering systems are sophisticated and evaluate the sender's entire behavior and history. This includes the reputation of the specific domain being used, the sending IP address, and the correctness of email authentication.
Any significant change in sending parameters, whether it's the domain, IP, or authentication setup, can temporarily impact deliverability as Gmail's machine learning systems adjust. This explains why an abrupt shift from a .com to a new .us domain, even with the same content, might experience issues. The system needs to re-learn and re-establish trust for the new identifier.
The history of the .us domain itself also plays a role. If a domain was previously used for spam or had a poor reputation, even if it's new to you, that history can linger and affect deliverability. This is why it's always recommended to understand the history of any domain you acquire for email sending. You can learn more about how a domain change affects email deliverability in our related content.
Conclusion
While .us domains are not inherently problematic for Gmail deliverability, new .us domains may indeed face heightened scrutiny compared to new .com domains. This seems to stem from a combination of starting with no reputation and a subtle, possibly algorithm-driven, caution associated with less common TLDs in their nascent stages.
The success of sending from a new .us domain to Gmail hinges on a meticulous warm-up strategy, consistent authentication, and careful monitoring of bounce rates and engagement. By doing so, you can build the necessary trust with ISPs and ensure your emails reach the inbox effectively, regardless of your domain extension.
Views from the trenches
Best practices
Start new domains, including .us, with a very slow and gradual warm-up process.
Ensure SPF, DKIM, and DMARC are correctly set up and aligned for your sending domain.
Monitor your domain's reputation using tools like Google Postmaster Tools (if enough volume is sent).
Common pitfalls
Sending large volumes of emails immediately from a new .us domain to Gmail accounts.
Ignoring bounce messages and low reputation warnings, especially for new domains.
Failing to implement proper email authentication, leading to perceived legitimacy issues.
Expert tips
If a new .us domain is struggling, consider testing a .com domain with identical setup and volume to compare deliverability.
Focus on high engagement from recipients during the warm-up phase to send positive signals to ISPs.
Understand that deliverability is about inbox placement, not just successful delivery without bounces.
Marketer view
Marketer from Email Geeks says that new domains, especially those registered within the last 90 days, often struggle because they lack an established track record and reputation.
2020-11-20 - Email Geeks
Marketer view
Marketer from Email Geeks says that Google Postmaster Tools might not show data for very low sending volumes, especially if emails are being blocked outright.
gmail.com users. While common wisdom suggests the TLD itself isn't the primary factor, recent experiences and observations indicate that new .us domains might face specific hurdles, particularly with getting into the inbox.
Google. This lack of a track record can make the initial sending phase, often referred to as 'warming up', challenging. When a new domain, especially one that isn't a traditional .com, starts sending email, ISPs are naturally cautious.
Google Postmaster Tools might not provide sufficient data for very low volumes, making diagnosis difficult.
Gmail's new sender guidelines to ensure compliance.
Yahoo have recently tightened their requirements, making authentication a critical factor for inbox placement. A strong authentication setup signals to receiving servers that your email is legitimate and authorized. We offer a simple guide to DMARC, SPF, and DKIM to help you configure these essential records.
