Do I need to warm up a new domain for a small email list?
Michael Ko
Co-founder & CEO, Suped
Published 3 May 2025
Updated 19 Aug 2025
8 min read
Starting with a new domain for email sending always brings questions about deliverability. The common advice is to warm up your domain, gradually increasing your sending volume to build a positive sender reputation with internet service providers (ISPs). This process helps them recognize your domain as legitimate, ensuring your emails reach the inbox rather than the spam folder. However, when dealing with a small email list, the rules can be a bit different.
The necessity of warming up a new domain largely depends on your sending volume and the age of your domain. While a gradual ramp-up is crucial for high-volume senders, a smaller list might not require the same intensive process. Understanding the nuances of sender reputation and how ISPs evaluate email traffic is key to making an informed decision for your specific situation.
For small lists, the risks associated with sudden high volumes are naturally mitigated. However, that doesn't mean you can skip all best practices. Even with a small list, foundational elements like proper domain setup and consistent sending patterns remain important for healthy email deliverability.
Understanding sender reputation
Sender reputation is the cornerstone of successful email deliverability. ISPs (like Google and Yahoo) use a variety of factors to assess a sender's trustworthiness, including volume, bounce rates, spam complaints, and engagement. A new domain has no sending history, meaning it lacks a pre-established reputation. This lack of history makes ISPs cautious.
The concern arises because spammers often use brand new domains to send large volumes of unsolicited email. ISPs are designed to detect and block these patterns. A sudden surge of email from an unknown domain can trigger red flags, even if your intentions are legitimate. This is where the concept of warming up comes into play, creating a gradual, positive sending history that reassures ISPs.
However, for extremely small lists, such as 100 contacts sent once per week, the volume is often too low to significantly impact reputation, whether positively or negatively, in the way large-scale sending does. It's more about statistical noise than a robust reputation signal.
When is domain warming necessary?
For most senders, warming up a new domain is essential. If you're planning to send thousands or tens of thousands of emails, a structured warm-up plan is non-negotiable. This involves starting with a small number of emails and slowly increasing the volume over several weeks or even months. The goal is to demonstrate consistent, positive sending behavior to ISPs.
When you have a very small list, like 100 contacts, and are sending infrequently (e.g., once a week), a formal warm-up might not be strictly necessary, especially if your domain is already over 30 days old. ISPs typically focus on patterns associated with bulk sending. Your primary concern should be maintaining good list hygiene and sending engaging content.
However, if the domain is truly brand new (less than 30 days old) and you're sending any volume, even a small one, it's prudent to still proceed with caution. The risk isn't so much about volume, but about being an unknown entity. In these cases, a gentle ramp-up, focusing on highly engaged contacts first, is a smart approach. Think of it as introducing yourself politely to the internet.
It's also important to differentiate between warming up an entire domain versus a specific subdomain or IP address. Each has its own considerations. For instance, new domains on shared IPs for transactional emails might still need a mindful ramp-up, even if it's less formal than for marketing sends.
Essential steps for new domains, regardless of list size
Even if a formal warm-up isn't required for your small list, there are crucial foundational steps and best practices you should follow for any new domain to ensure optimal deliverability from day one.
Properly setting up your domain's DNS records is non-negotiable. This includes SPF, DKIM, and DMARC. These authentication protocols prove that your emails are legitimate and prevent spoofing. Without them, your emails are highly likely to land in the spam folder, regardless of your sending volume.
Essential DNS records
Ensure these records are correctly configured for your new domain.
SPF record: Specifies which servers are authorized to send emails on behalf of your domain. SPF (Sender Policy Framework) helps prevent spoofing.
DKIM record: Adds a digital signature to your emails, verifying they haven't been tampered with. This enhances trust and improves deliverability.
DMARC record: Builds upon SPF and DKIM, telling receiving servers what to do with emails that fail authentication. Implement a DMARC policy from day one.
Even with a small list, it's beneficial to have a functional website for your new domain. This adds to your domain's credibility. It doesn't have to be complex; a simple page or even a redirect to your main company website is sufficient. This signals to ISPs that your domain is part of a legitimate online presence.
Finally, consider sending a whitelisting campaign to your existing contacts if you are switching domains. Inform them about the new From address and ask them to add it to their address books or contact lists. This crowdsourced whitelisting is a strong signal to mailbox providers and can give you a significant reputation boost, effectively bypassing many spam filters.
The pitfalls of automated warming tools
While the idea of automating domain warm-up with a service might sound appealing, especially for busy marketers, it's often a perilous path. Many of these services operate by sending emails to a network of fictitious or unengaged accounts (often Gmail accounts), which doesn't accurately reflect real sending behavior or engagement.
ISPs are highly sophisticated at detecting these artificial patterns. Sending mail to accounts that aren't real customers or don't engage with your content can raise red flags rather than build a genuine reputation. This can lead to your domain being flagged, blacklisted (or blocklisted), or having your emails routed directly to spam, undermining all your efforts.
Furthermore, some of these automated tools may violate the terms of service of major email providers, including Google. If detected, this could lead to deliverability issues that are far more severe than simply having a new, unwarmed domain. The best warming strategy is always to send authentic emails to real, engaged subscribers at a natural pace.
When small volume sends face big problems
A common scenario where deliverability issues arise, even with small volumes, is when using shared IPs or platforms. For example, if you were using a CRM that was also used by spammers, your domain could get caught in the crossfire, regardless of your personal sending habits.
This highlights the importance of choosing a reputable Email Service Provider (ESP) or a self-hosted solution that maintains high deliverability standards. If your provider's shared IP space or platform has a poor reputation due to other users, it can negatively impact your own emails, even if your domain practices are impeccable.
Views from the trenches
Best practices
Send email slowly and gradually increase volume to build reputation organically.
Ensure the new domain has an MX record and a functional website, even a redirect.
Ramp up volume with real content to real customers through your actual ESP, not artificial services.
Common pitfalls
Relying on automated 'warm-up services' that often employ questionable tactics and can harm your sender reputation.
Small SaaS platforms can inadvertently become targets for spammers, leading to deliverability issues.
Automated warm-up tools may violate service terms of major providers like Google, potentially leading to penalties.
Expert tips
For very small lists (e.g., under 100 emails per week), significant warming is often unnecessary if the domain is over 30 days old.
Email reputation for smaller volumes is based on statistical noise rather than strong signals.
Warm-up is typically crucial for lists in the thousands or tens of thousands of emails.
Expert view
Expert from Email Geeks says the best approach is to send email slowly and gradually, building your sender reputation organically rather than relying on automated tools.
2024-01-04 - Email Geeks
Expert view
Expert from Email Geeks says for lists of 100 contacts or fewer, warming isn't typically required unless the domain is less than 30 days old.
2024-01-04 - Email Geeks
Final thoughts on warming small lists
For a new domain sending to a small email list (around 100 contacts weekly), a rigorous, formal warm-up process with automated tools is generally not necessary, and can even be detrimental. Your sending volume is likely too low to register as bulk sending, which is what ISPs primarily focus on for warm-up purposes.
Instead, prioritize fundamental email deliverability best practices. This includes ensuring your domain has correctly configured authentication records (SPF, DKIM, DMARC), maintaining a clean and engaged email list, and consistently sending valuable content. Having a simple website associated with your domain also adds credibility.
If you are concerned about migrating your existing list to a new domain, especially if it's a cold list, a gentler approach is still recommended. Focus on re-engaging segments of your list over time, starting with the most active contacts. For comprehensive guidance on specific scenarios, like warming a domain for cold contacts, review specific resources tailored to those situations.
In essence, for small, engaged lists, your focus should be on consistent, quality sending and robust authentication, not on complicated or artificial warm-up routines. By adhering to these principles, you can achieve excellent deliverability without unnecessary steps.
Google and 
Yahoo) use a variety of factors to assess a sender's trustworthiness, including volume, bounce rates, spam complaints, and engagement. A new domain has no sending history, meaning it lacks a pre-established reputation. This lack of history makes ISPs cautious.
Google. If detected, this could lead to deliverability issues that are far more severe than simply having a new, unwarmed domain. The best warming strategy is always to send authentic emails to real, engaged subscribers at a natural pace.
