Should I use a subdomain or separate domain for marketing emails and cold outreach?

Summary

Experts, marketers, and documentation from various sources converge on the recommendation to separate email sending domains based on email type, particularly for cold outreach. Using the same domain for all email types, including cold emails, presents a substantial risk to the sender reputation and overall deliverability of important transactional and marketing emails. While subdomains provide a degree of segmentation and protection, a completely distinct domain is generally preferred for cold outreach due to its inherent risks and potential for negatively impacting the primary domain's reputation. A critical caveat to consider is that initiating a new email stream, be it on a subdomain or a completely separate domain, requires a proper warming-up process involving IPs and domains to establish a positive sending history.

Key findings

  • Domain Segregation is Key: Employing different domains contingent upon the kind of email—be it transactional, marketing, or cold outreach—is fundamental for preserving a sound sender reputation.
  • Inherent Risks of Cold Outreach: Cold outreach is identified as the most considerable risk factor, which can potentially damage domain reputation through spam complaints and ensuing deliverability complications.
  • Subdomains offer Partial Protection: Subdomains can afford partial protection for marketing campaigns; however, opting for an entirely separate domain is more prudent when engaging in cold outreach to maximize risk mitigation.
  • Reputation Erosion Equals Delivery Issues: A compromised domain reputation almost invariably leads to emails being funneled into spam directories, thereby adversely affecting overall email performance metrics.
  • The Warming-Up Imperative: Warming up new Internet Protocol addresses and domains is considered vital as it facilitates the gradual buildup of a reputable sending record.
  • Cold IP Risks: Using dedicated IPs for cold email increases the risk of IP blocking.
  • Subdomain Content Needs: Subdomains should contain distinct content to improve deliverability and reputation management.

Key considerations

  • Proactive Reputation Management: Consistent monitoring and management of your domain reputation are imperative to guarantee optimal email delivery rates.
  • Traffic Segmentation: Channeling email traffic depending on its category facilitates a more organized and effective approach to reputation management.
  • Diversify Registrars for Added Isolation: Engaging a separate domain registrar for cold email campaigns can provide an extra layer of isolation, further minimizing potential risks.
  • Balancing Sending Volume: Mindful management of sending volumes, coupled with a carefully phased increase during the warming-up period, is conducive to establishing a robust sending foundation.
  • Elevate Content Quality: Diligent efforts to enhance the quality of email content, notably within cold outreach initiatives, can significantly curtail the likelihood of triggering spam alerts.
  • Strategic Cold Emailing: Carefully consider the cold email strategy to minimize potential negative impacts on domain reputation.
  • Content Strategy: Develop a content strategy that utilizes subdomains for organized website content and SEO benefits.
  • Authentication Setup: Ensure correct setup and maintenance of email authentication protocols to improve email deliverability.

What email marketers say
12Marketer opinions

The consensus among email marketers and experts is that using separate domains for different email types, especially cold outreach, is crucial for maintaining a good sender reputation and deliverability. Using the same domain for all email types, especially cold emails, poses a risk to your primary domain's reputation, potentially affecting the deliverability of important transactional and marketing emails. While subdomains can offer some level of segmentation and protection, a completely separate domain is generally recommended for cold outreach due to its inherent risks. Warming up new domains and IPs is essential when starting any new email stream.

Key opinions

  • Domain Separation: Using separate domains for different email types (transactional, marketing, cold outreach) is a best practice to protect sender reputation.
  • Cold Email Risks: Cold outreach poses the highest risk to domain reputation due to potential spam complaints and deliverability issues.
  • Subdomain Usage: Subdomains can offer some protection for marketing emails, but a separate domain is preferred for cold outreach.
  • Reputation Impact: A poor domain reputation can lead to emails being sent to spam folders, negatively impacting overall email performance.
  • Warming Up: Warming up new IPs and domains helps build a positive sending reputation gradually.

Key considerations

  • Domain Reputation: Regularly monitor and maintain your domain reputation to ensure optimal email deliverability.
  • Email Segmentation: Segment your email traffic by type (transactional, marketing, cold) to manage reputation effectively.
  • Separate Registrar: Consider using a different registrar for cold email domains to further isolate risks.
  • Sending Volume: Be mindful of sending volumes and gradually increase them when warming up new domains or IPs.
  • Content Quality: Ensure the content quality of all emails, particularly cold outreach, to minimize spam complaints.
Marketer view

Email marketer from Lemlist explains that one of the most important things to consider is your sender reputation, especially when it comes to cold emails. With the use of a separate domain you can make sure your primary domain reputation isn't at risk.

October 2022 - Lemlist
Marketer view

Email marketer from Sales Hacker Forum strongly advises against using the same domain for cold outreach as for regular business communications. They advocate for a separate domain with a different registrar.

December 2022 - Sales Hacker Forum
Marketer view

Marketer from Email Geeks recommends warming up IPs and domains when starting new ones.

August 2023 - Email Geeks
Marketer view

Email marketer from GMass Blog states that you should never send cold email from your primary domain. Use a separate domain name that’s similar to your primary domain. This protects your main domain’s deliverability and sender reputation.

November 2022 - GMass Blog
Marketer view

Email marketer from Woodpecker Blog suggests that a poor domain reputation can result in emails being sent to the spam folder, that's why you should separate your cold and marketing emails from your transactional emails to protect your reputation.

October 2023 - Woodpecker Blog
Marketer view

Marketer from Email Geeks clarifies that cold emails should be set up on its own IP away from the root domains IP, but it doesn't necessarily have to be dedicated.

July 2023 - Email Geeks
Marketer view

Email marketer from Reddit recommends using a completely separate domain for cold outreach. This user emphasizes the importance of protecting your primary domain's reputation, especially considering the risks associated with cold email.

December 2022 - Reddit
Marketer view

Marketer from Email Geeks advises against using the same domain for cold emails as for corporate, marketing, or transactional emails. Suggests investigating and fixing the root domain's reputation, as it can affect subdomains. Also suggests to stop all cold emailing out of the root domain immediately.

August 2023 - Email Geeks
Marketer view

Email marketer from Reddit explains that using a subdomain for marketing emails is generally a good idea to protect the main domain's reputation, especially if you're unsure about the list quality or sending practices.

November 2021 - Reddit
Marketer view

Email marketer from MailerQ Blog explains that sender reputation is linked to the domain you use to send emails. If your marketing emails are causing problems for your transactional emails, you should consider using a separate domain. A separate domain can protect the main domain.

May 2021 - MailerQ Blog
Marketer view

Email marketer from Email Marketing Forum explains that using a subdomain allows for segmentation of email types, making it easier to track performance and manage reputation for each category.

December 2021 - Email Marketing Forum
Marketer view

Email marketer from Hunter.io Blog explains that for cold outreach, using a separate domain (or even multiple) is a best practice. This isolates the risk to the reputation of the cold email domain without negatively impacting the primary domain used for business operations.

April 2022 - Hunter.io Blog

What the experts say
4Expert opinions

Experts emphasize the importance of careful domain and IP management for email deliverability, especially when dealing with cold outreach. Using dedicated IPs for cold emails may lead to blocking, and separate domains are considered essential to isolate the impact of cold email practices on the primary domain's reputation. Subdomains can be used for segmentation but should contain distinct content to manage deliverability and reputation effectively.

Key opinions

  • IP Blocking: Dedicated IPs for cold email increase the risk of IP blocking.
  • Domain Isolation: Separate domains are crucial for cold outreach to protect the primary domain's reputation.
  • Subdomain Content: Subdomains should contain distinct content to improve deliverability and reputation management.
  • Deliverability Impact: Subdomains can be treated almost as separate domains for deliverability considerations.

Key considerations

  • Cold Email Strategy: Carefully consider the cold email strategy to minimize potential negative impacts on domain reputation.
  • Content Segmentation: Segment content effectively across different subdomains to improve email traffic management.
  • Sending Volume: Maintain lower sending volumes for cold outreach to reduce the risk of damaging the domain's reputation.
  • Reputation Monitoring: Regularly monitor and assess domain and IP reputation to identify and address any deliverability issues.
Expert view

Expert from Email Geeks explains that using a dedicated IP for cold emails will likely result in IP blocking. They note that many cold email products use O365 and Google Workspace plugins to avoid this.

July 2023 - Email Geeks
Expert view

Expert from Spam Resource explains that using a separate domain for cold outreach is essential because the sending volumes and content nature can drastically impact your primary domain's reputation. A lower volume of carefully targeted emails from a separate domain minimizes risk.

June 2024 - Spam Resource
Expert view

Expert from Word to the Wise, Steve Jones explains that you should think of a subdomain in almost the same way as you think of a completely different domain for deliverability.

June 2024 - Word to the Wise
Expert view

Expert from Word to the Wise explains that subdomains should have distinct content. Using different subdomains helps in segmenting your email traffic, which makes managing your domain reputation easier.

April 2024 - Word to the Wise

What the documentation says
4Technical articles

Email deliverability documentation from various providers highlights the importance of domain and IP management for maintaining a positive sender reputation. Google recognizes subdomains as part of the main domain but acknowledges their potential for independent rankings. Email service providers like SparkPost, SendGrid, and Mailchimp advocate for dedicated sending domains and proper email authentication to improve deliverability and protect brand reputation.

Key findings

  • Subdomain Organization: Subdomains help organize website content and can have individual search rankings.
  • Dedicated Domains: Dedicated sending domains improve email deliverability and reputation management.
  • IP Differentiation: Using dedicated IP addresses for different email types is essential for good sender reputation.
  • Authentication Importance: Email authentication (SPF, DKIM, DMARC) protects brand reputation and improves deliverability.

Key considerations

  • Content Strategy: Develop a content strategy that utilizes subdomains for organized website content and SEO benefits.
  • Domain Strategy: Implement a domain strategy that uses dedicated sending domains to optimize email deliverability.
  • Reputation Monitoring: Continuously monitor and manage domain reputation across all sending sources.
  • Authentication Setup: Ensure correct setup and maintenance of email authentication protocols to improve email deliverability.
Technical article

Documentation from Mailchimp explains that using a dedicated sending domain, or authenticating your sending domain, helps improve email deliverability and protects your brand's reputation.

August 2023 - Mailchimp
Technical article

Documentation from SendGrid explains the importance of using dedicated IP addresses and domains for different types of email (transactional vs. marketing) to maintain a good sender reputation and improve deliverability.

July 2022 - SendGrid
Technical article

Documentation from Google Search Central states that using subdomains can help organize your website content and that Google treats subdomains as part of the main domain, but they can still have their own rankings.

March 2022 - Google Search Central
Technical article

Documentation from SparkPost Support explains the benefits of dedicated sending domains, including improved deliverability and reputation management, which are crucial for both marketing and transactional emails.

October 2021 - SparkPost Support