Do blacklists exist for newly registered domain names?
Michael Ko
Co-founder & CEO, Suped
Published 1 Jul 2025
Updated 19 Aug 2025
6 min read
When you register a new domain name, a common concern that crosses many minds is whether it will immediately end up on an email blacklist or blocklist. It's a valid question, especially given the strict filtering policies of internet service providers (ISPs) and email providers. The short answer is no, newly registered domain names (NRDs) aren't automatically added to major blacklists just because they are new.
However, NRDs are indeed viewed with a higher degree of suspicion. This heightened scrutiny isn't about penalizing legitimate new businesses. Instead, it's a necessary measure to combat the widespread abuse of new domains by malicious actors, such as spammers, phishers, and malware distributors. Understanding this nuance is crucial for anyone planning to use a newly registered domain for email communication and ensuring good email deliverability.
Newly registered domains (NRDs) are a favorite tool for cybercriminals. The ease and low cost of registering new domains allow them to quickly set up operations for phishing campaigns, malware distribution, and large-scale spam runs. These domains are often used for a short period, sometimes just a few days, before being discarded or retired when they inevitably get blocklisted.
Due to this widespread abuse, many threat intelligence services, cybersecurity firms, and major email providers implement systems to monitor NRDs closely. They leverage various data points, including WHOIS information, DNS changes, and initial traffic patterns, to identify suspicious new domains. While a domain won't be immediately put on a public blacklist, it will certainly be flagged for observation.
Some organizations even proactively block traffic to newly registered domains for a specific period, such as 14 to 30 days. This practice, while sometimes causing false positives, is an effective defense against rapidly deployed malicious campaigns. It's a trade-off between convenience and security, aimed at protecting users from potential threats before they can cause harm.
The inherent risk associated with NRDs means that legitimate senders using a new domain must be extra diligent in establishing a positive sender reputation. It's not about being on a blacklist from day one, but about avoiding actions that could quickly lead to one.
Understanding newly seen domains (NSDs)
Newly Seen Domains (NSDs) are a critical concept for email deliverability. These are domains that have been observed for the very first time within a short period, typically 24-48 hours. Many security systems categorize and monitor NSDs separately because of the high likelihood that they are associated with temporary malicious activities.
If your email traffic originates from an NSD, it might face stricter scrutiny, temporary deferrals, or even outright rejection by receiving mail servers, even before your domain accumulates a negative reputation. This initial caution by receivers is a defense mechanism against spam and phishing campaigns that often originate from freshly created domains.
How blacklists (and blocklists) perceive NRDs
Traditional blacklists (or blocklists) such as those maintained by Spamhaus (like the Domain Blocklist - DBL) do not automatically add domains based solely on their registration date. These lists typically rely on evidence of abusive behavior. However, newly registered domains are put on a shortlist, with a significantly higher risk of being listed if any suspicious activity is detected.
While public blacklists might not list NRDs immediately, many organizations proactively implement their own internal blocklists based on domain age. For instance, some security systems automatically block queries to newly registered domains for a period of 15 days or more, considering this a strong defense against rapidly emerging threats. This means your new domain could be blocked by certain recipients even without being on a major public blacklist.
The key factor for any domain, especially new ones, is its sender reputation. ISPs track a domain's history, including when they first saw mail from it and the last time they observed activity. A brand-new domain with no history has no inherent reputation, which makes it a blank slate. Any misstep, such as sending to invalid addresses or generating spam complaints, can quickly lead to a poor reputation and subsequent blacklisting.
Understanding how email blacklists work is essential. They are reactive, not proactive, when it comes to age. They respond to behavior, but new domains are watched more closely, shortening the leash for any questionable activity. This makes building a positive domain reputation from day one absolutely critical.
Behavior: Gradual email volume increase (warming up), engagement-driven sending, adhering to email best practices. Focus on quality.
Outcome: Builds positive domain reputation over time, leading to good inbox placement. Avoids blacklists and ensures deliverability.
Malicious NRD use
Purpose: Phishing, spam, malware distribution, command and control servers. Short-term, high-volume abuse.
Behavior: Immediate high-volume sending, sending to purchased or scraped lists, ignoring bounce and complaint rates.
Outcome: Rapid blacklisting (or blocklisting) by various providers, leading to emails consistently landing in spam folders or being rejected.
Building a positive reputation for your new domain
To navigate the cautious landscape of newly registered domains, proactive measures are essential. The goal is to signal to ISPs and email providers that your domain is legitimate and trustworthy. This begins with properly setting up your domain's email infrastructure.
First, implement robust email authentication protocols: SPF, DKIM, and DMARC. These records verify that your emails are truly coming from your domain and haven't been spoofed, a common tactic used by malicious NRDs. Correct authentication immediately boosts your credibility.
Next, focus on domain and IP warming. Start by sending a low volume of emails to engaged subscribers, gradually increasing the volume over several weeks or months. This process builds a positive sending history with ISPs, showing them that your domain sends desired mail. Skipping this can trigger spam filters, as sudden high volumes from a new domain are a red flag.
Maintain pristine email lists. Sending to inactive or invalid addresses, or generating high spam complaints, will quickly land your domain on a blacklist. Regularly clean your lists and prioritize sending only to those who have explicitly opted in. This proactive approach ensures your email domain reputation remains positive.
Factor
Impact on new domain
Domain age
Newness itself flags domain for higher scrutiny initially.
Email volume
Sudden high volume from new domain is suspicious.
Email authentication (SPF, DKIM, DMARC)
Proper setup signals legitimacy and improves trust.
Spam complaints
High rates quickly lead to blacklisting.
Bounce rate
High rates from invalid addresses are a red flag.
Conclusion
While blacklists don't automatically list newly registered domains, the email ecosystem treats them with initial skepticism due to prevalent malicious activities. Successfully using a new domain for email communication hinges on establishing a strong, positive sender reputation from the outset.
By implementing proper authentication, carefully warming up your sending volume, and maintaining a clean and engaged subscriber list, you can overcome this initial hurdle and ensure your legitimate emails consistently reach the inbox.
Views from the trenches
Best practices
Always warm up a newly registered domain gradually to build sender reputation, avoiding large sends.
Implement SPF, DKIM, and DMARC immediately for any new domain to establish trust.
Monitor your domain's sending performance closely in the first few weeks for any issues.
Ensure your email content is relevant and engaging to encourage positive recipient interactions.
Common pitfalls
Sending high volumes of email immediately after registering a new domain.
Not implementing email authentication protocols like SPF, DKIM, and DMARC.
Sending to unverified or old email lists, leading to high bounce rates and complaints.
Ignoring early signs of deliverability issues, like increased spam folder placement.
Expert tips
Pay close attention to changes in your domain's name server, as ISPs monitor this too.
Consider a longer warm-up period than usual for critical email operations on new domains.
Actively seek to be whitelisted by major ISPs once your domain has a solid sending history.
Invest in tools that provide visibility into how ISPs perceive your domain's reputation.
Marketer view
Marketer from Email Geeks says DBL (Domain Blocklist) might put newly registered domains on a shortlist, increasing their risk of being listed.
2019-08-13 - Email Geeks
Marketer view
Marketer from Email Geeks says major ISPs likely have their own access to newly registered domain lists and use this information for reputation scoring.
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