Checklist For Setting Up Cold Email Domains
- Silvio Bonomi
- Sep 3
- 11 min read
Updated: Oct 22
Setting up a dedicated domain for cold email outreach is critical to protect your primary domain's reputation and ensure your messages land in inboxes, not spam folders. Here's how to do it:
Use a Separate Domain: Avoid using your main domain for cold outreach to safeguard its sender reputation.
Choose the Right TLD: Opt for trusted extensions like or for better deliverability.
Register with a Reliable Provider: Use reputable registrars like Google Domains, Cloudflare, or Namecheap.
Authenticate Your Domain: Set up SPF, DKIM, and DMARC records to verify your emails and prevent spoofing.
Warm Up Your Mailboxes: Gradually increase email volume over 2–4 weeks to build trust with email providers.
Monitor Performance: Track delivery, open, and reply rates to identify and fix any issues early.
Maintain Long-Term Health: Regularly update DNS records and check for blacklisting to keep your domain performing well.
These steps create a solid foundation for effective email campaigns while minimizing risks to your primary communications.
Choosing and Registering Your Cold Email Domain
Why You Need a Separate Domain for Cold Outreach
Using your primary domain for cold email campaigns can jeopardize your sender reputation. Email service providers evaluate domains independently, so if your cold email domain encounters issues - like being flagged for spam - your main domain remains unaffected. This separation offers the freedom to test outreach strategies, refine messaging, and scale campaigns without risking the integrity of your primary domain.
This approach also ensures that your essential communications, like client emails or internal operations, remain uninterrupted. Your main domain handles critical business correspondence, while your cold email domain focuses solely on lead generation and outreach.
Once you've decided to use a separate domain, the next step is choosing one that supports your email deliverability goals.
Picking the Right Top-Level Domain (TLD)
Your choice of domain extension, or TLD, directly affects email deliverability. Email providers often associate certain TLDs with trustworthiness, which influences whether your emails land in the inbox or the spam folder.
.com domains are the most reliable choice. They’re widely trusted by both email providers and recipients, making them ideal for cold outreach. Plus, their familiarity often boosts engagement since recipients are more comfortable with .com addresses.
.net domains are a strong backup option. While slightly less common, they still convey professionalism and achieve solid deliverability rates.
Newer TLDs like .io, .co, and .ai are gaining traction, particularly in tech-focused industries. While they may face stricter scrutiny from spam filters, they can resonate well with audiences in those niches.
Here’s a quick breakdown of TLDs and their pros and cons:
Steer clear of country-specific TLDs unless you're targeting that specific region. Extensions like .tk, .ml, or .ga often have a poor reputation and are frequently flagged as spam.
Registering Your Domain with Trusted Providers
Once you’ve selected a TLD, it’s time to register your domain with a reputable provider. A trusted registrar ensures better support, enhanced security, and seamless integration for setting up email authentication and DNS records - key factors for successful cold email campaigns.
Here are some reliable options for domain registration:
Google Domains (now part of Squarespace): Offers smooth integration with Google Workspace and easy DNS management.
Cloudflare: Known for competitive pricing, robust security features, and excellent DNS tools.
Namecheap: Provides good value with free privacy protection and an intuitive interface.
Before finalizing your purchase, check the domain’s history using tools like MXToolbox or Barracuda Reputation Block List. This ensures the domain hasn’t been blacklisted, which could harm your email deliverability from the start.
To protect your personal information, enable domain privacy protection during registration. This prevents your details from being listed in WHOIS databases, reducing spam and enhancing security.
Finally, register your domain for at least two years. This signals stability to email providers, reducing the likelihood of being flagged as temporary or suspicious. Many experienced outreach professionals even opt for three to five years upfront to build trust and credibility over time.
Do you need a new domain for cold emailing?
Setting Up Your Email Domain Configuration
Once your domain is registered, the next step is configuring your email settings. This process is crucial for improving email deliverability, and while it requires attention to detail, doing it right from the start can save you a lot of trouble later.
Creating Mailboxes with a Trusted Email Service Provider
Using a reliable email service provider like Google Workspace or Microsoft 365 is key to ensuring your emails are delivered and perceived as legitimate. Google Workspace offers the familiar Gmail interface, which can help build trust with recipients, along with Google's strong sender reputation. Similarly, Microsoft 365 is a great choice, especially for B2B outreach, as many businesses already use Outlook.
For cold email campaigns, avoid free email services like Gmail.com or Outlook.com. These limit your control over important authentication settings and are more likely to trigger spam filters. Instead, set up 3-5 professional email addresses (e.g., firstname.lastname@yourdomain.com or sales@yourdomain.com). This spreads your sending volume across multiple addresses, reducing the chances of any single mailbox being flagged.
Once your mailboxes are ready, move on to authenticating your domain by setting up SPF, DKIM, and DMARC records.
Setting Up DNS Records for Email Authentication
DNS records are the backbone of email authentication, ensuring your emails are trusted and protecting your domain from spoofing attempts. Three key records - SPF, DKIM, and DMARC - work together to verify your identity as a sender.
SPF (Sender Policy Framework): This record specifies which servers are allowed to send emails on behalf of your domain. It helps prevent spammers from impersonating you. For example, if you're using Google Workspace, add to your SPF record. For Microsoft 365, use . Always end your SPF record with instead of to allow DMARC to validate DKIM signatures, which is critical for cold email campaigns.
DKIM (DomainKeys Identified Mail): DKIM adds a digital signature to your emails, ensuring they haven't been tampered with and verifying the sender's identity. To set this up, generate a key pair in your email provider's admin console and add the public key as a TXT record in your DNS settings. The record name usually follows the format , where "selector" is a unique identifier provided by your email service.
DMARC (Domain-based Message Authentication, Reporting, and Conformance): DMARC combines SPF and DKIM results to enforce authentication policies. This record tells email servers how to handle messages that fail authentication - whether to deliver, quarantine, or reject them. Start with a policy of to monitor results without affecting delivery. Include a reporting email address to receive detailed insights into authentication failures, allowing you to fine-tune your setup.
Starting February 2024, Google and Yahoo will require SPF and DKIM for all bulk senders, with DMARC becoming mandatory for those sending over 5,000 emails daily. Microsoft Outlook.com will enforce similar rules starting May 5, 2025, for domains exceeding 5,000 daily emails.
According to Valimail, "75% to 80% of domains that have published a DMARC record face challenges in achieving enforcement (‘p=none’ to stricter policies)".
This highlights the importance of thorough initial setup and gradually tightening your policies as your domain builds a solid reputation.
Wrap up your configuration by setting up MX and PTR records to ensure seamless email routing and better deliverability.
Configuring Reverse DNS (PTR) and MX Records
MX (Mail Exchange) records direct incoming emails to your domain's email servers. These records include priority levels, which determine the order in which servers are contacted. For Google Workspace, you'll typically add five MX records pointing to servers like and . Microsoft 365 usually requires a single MX record pointing to your tenant-specific server, such as .
Reverse DNS (PTR) records link IP addresses back to domain names, helping email providers confirm the legitimacy of the sending server. For Google Workspace and Microsoft 365, PTR records are managed automatically. However, if you're using a dedicated IP or specialized email service, ensure the PTR record matches your sending domain or email provider's domain.
During testing, set the TTL (Time to Live) to 300 seconds for quick propagation. Once stable, increase it to 3600 seconds.
Use tools like MXToolbox or Google's Admin Toolbox to verify your DNS configuration. These tools check the syntax and propagation of your SPF, DKIM, DMARC, and MX records and ensure everything is set up correctly across global DNS servers.
The FBI recently reported that Business Email Compromise (BEC) scams have caused $55 billion in losses. This underscores why email providers are so strict about authentication. Proper DNS configuration not only safeguards your domain's reputation but also protects recipients from potential threats, making this step essential for successful cold email campaigns.
Warming Up Your New Mailboxes
Once your DNS records and email authentication are set up, your new mailboxes need a gradual introduction to email providers. This "warm-up" period helps build trust with major providers like Gmail, Outlook, and Yahoo. These companies closely monitor new domains and senders, so easing into email activity is crucial for maintaining strong deliverability. Think of it as laying the groundwork for successful outreach campaigns.
Step-by-Step Warm-Up Process
Typically, warming up a mailbox takes 2–4 weeks. During this time, gradually increase the number of emails sent each day:
Week 1: Start small, sending 5–10 emails daily from each mailbox. Focus on sending emails to your internal team or trusted contacts who are likely to engage. This helps establish positive sender signals.
Week 2: Increase to 15–25 emails per day per mailbox. Begin mixing in prospects with your trusted contacts, but still prioritize recipients who are likely to interact with your emails.
Week 3: Scale up to 30–50 emails daily per mailbox. Start targeting your ideal customer profile more actively, but keep monitoring engagement closely.
Week 4 and beyond: Gradually work up to your target volume, often 50–100 emails per day per mailbox for cold outreach. Continue monitoring performance to ensure deliverability remains strong.
Consistency is key. Avoid sending emails in large bursts, and schedule them during regular business hours (9:00 AM to 5:00 PM) in the timezone of your target audience. This approach protects your domain reputation and sets you up for scalable outreach.
Using Automated Warm-Up Tools
For those managing multiple mailboxes, automation can simplify the warm-up process. Automated tools mimic natural email activity by sending and receiving messages between real accounts, which helps build positive engagement patterns and boosts your sender reputation.
For example, Warmbox is a popular tool that automates email sending and tracks engagement. Other platforms, like Mailshake, include built-in warm-up features, while Lemwarm specializes in improving Gmail and Google Workspace deliverability by simulating conversational email exchanges. Running these tools for at least 30 days can help establish a solid sender reputation.
Once you’ve set up automation, keep an eye on your metrics to ensure the warm-up process is working as intended.
Tracking Engagement Metrics
Monitoring your performance during the warm-up phase is crucial to identify potential issues early. Keep track of these key metrics:
Delivery Rates: Aim for delivery rates above 95%. If you notice a spike in bounced or rejected emails, slow down your sending pace and double-check your authentication settings.
Open Rates: While open rates can vary depending on your audience and subject lines, significant declines could signal deliverability problems.
Reply Rates: Encourage replies by asking simple questions or sharing useful information. Positive engagement boosts your sender reputation.
Spam Folder Placement: Use tools like Mail Tester or GlockApps to ensure your emails land in inboxes rather than spam folders.
Document daily send volumes, delivery rates, open rates, and any anomalies for each mailbox. This tracking helps you spot patterns and make adjustments as needed.
For businesses running large-scale outbound campaigns, services like Artemis Leads integrate proper domain warm-up into their B2B lead generation strategies. By combining email and LinkedIn outreach, they ensure high-quality leads aren't lost due to deliverability issues.
If you encounter persistent problems - such as emails consistently landing in spam or low engagement rates - pause your campaigns and revisit your email setup. Even minor issues with DNS or authentication can have a big impact, so addressing them early can save you from long-term headaches.
Maintaining Your Domain and Reputation Long-Term
Setting up your domain is just the beginning. To ensure long-term success, regular upkeep and monitoring are essential. As email systems and security protocols evolve, staying proactive helps protect your domain and keeps your outreach efforts running smoothly.
Keep an eye on domain and mailbox health: Make it a habit to review and update your SPF, DKIM, and DMARC records. Anytime you switch platforms or add new email tools, these records need to be updated to maintain strong deliverability rates.
Even if you’re only using your domain for sending emails, publishing MX records is a smart move. Missing these records can lead to rejected emails. Adding a BIMI record is another great step - it not only displays your company logo but also helps reduce spoofing attempts while boosting brand visibility.
Don’t forget to check if your domain has been blacklisted. Tools like HetrixTools, EasyDMARC, or MXToolbox can help you stay on top of this. Monitoring your IP addresses is just as important since a blacklisted IP can seriously impact your email deliverability. If you’re using subdomains, make sure they have their own SPF, MX, and DKIM records to maintain consistent performance.
Conclusion: Building Email Infrastructure for Scalable Outreach
Creating a reliable email infrastructure for cold outreach lays the groundwork for long-term business growth.
Setting up a dedicated domain and configuring DNS records like SPF, DKIM, and DMARC protects your primary domain and establishes credibility with email providers. This technical setup acts as the backbone of your outreach efforts.
Once the basics are in place, the next step is warming up your mailboxes to ensure strong deliverability. Gradually increasing your sending volume over 2-4 weeks helps build trust with email providers, reducing the chances of landing in spam folders. This process is critical for achieving higher delivery rates and better engagement.
Ongoing maintenance, such as regular health checks and blacklist monitoring, ensures your system continues to perform well as your outreach scales. Pair this solid technical foundation with precise prospect targeting, and you’ll have a system capable of handling higher volumes without compromising results.
For even better outcomes, combine your email strategy with multi-channel outreach. Companies like Artemis Leads show how integrating a well-configured email domain with LinkedIn outreach can expand your reach and effectively cover your ideal customer profile. Investing time in building a strong email infrastructure pays off, creating a scalable, adaptable system that grows alongside your business.
FAQs
Why is it essential to set up SPF, DKIM, and DMARC for cold email outreach?
Setting up SPF, DKIM, and DMARC is essential to make sure your emails are trusted and successfully delivered. These protocols act as verification tools, confirming that emails sent from your domain are legitimate and not part of spoofing or phishing schemes.
When configured correctly, these records can boost your email deliverability, help bypass spam filters, and strengthen your sender reputation. These are all crucial elements for successful cold email campaigns, ensuring your messages land in the right inboxes while maintaining trust with your recipients.
What’s the best way to warm up new email mailboxes for better deliverability?
To get new email mailboxes off to a strong start, begin by sending 5–10 emails per day to recipients who are likely to engage with your messages. Gradually increase this number by 10–15% daily over a period of at least two weeks. This gradual approach builds trust with email providers and avoids triggering spam filters.
Before sending, ensure your domain is authenticated with protocols like SPF, DKIM, and DMARC. Use personalized, varied content and stick to emailing people who have explicitly opted in. Consistency is key - maintain regular sending patterns and prioritize positive interactions, such as high open rates and replies. These signals demonstrate your domain’s credibility to ISPs, boosting deliverability and minimizing the chances of emails landing in spam.
What risks could arise from not regularly monitoring my cold email domain's health?
Ignoring routine health checks for your cold email domain can cause major problems, like getting flagged as spam or even blacklisted. These issues can seriously hurt your email deliverability and engagement rates. When that happens, your messages are more likely to end up in spam folders, damaging your sender reputation and making your outreach efforts far less effective.
On the flip side, regular health checks help you keep a solid domain reputation, improve the chances of your emails landing in inboxes, and ensure your campaigns reach the right audience. This is key to maximizing the success of your outreach efforts.