Should I use a subdomain or separate domain for prospecting outreach emails to protect my sender reputation?

Summary

The overwhelming consensus from experts, marketers, and documentation is that using a separate domain, or at least a subdomain, for prospecting and outreach emails is crucial to protect the sender reputation of your primary domain. Outreach, especially cold outreach, is often viewed as spam, and can negatively impact deliverability. By isolating outreach activities to a separate domain, you prevent potential damage to your primary domain, which is critical for opt-in mail, corporate communications, and overall business operations. While both subdomains and separate domains offer protection, separate domains are generally recommended for maximum isolation. Furthermore, it is essential to 'warm up' any new domain or IP address used for sending before engaging in high-volume outreach. It is important to remember that a separate domain does not guarantee deliverability; the content, sending practices, and adherence to best practices are crucial to avoid spam filters.

Key findings

  • Reputation Protection: Separate domain/subdomain protects main domain's reputation.
  • Outreach = Risk: Outreach can damage sender reputation.
  • Isolate for Safety: Isolation prevents damage to important email streams.
  • Warm-Up Essential: New domains/IPs require warming up.
  • Not a Silver Bullet: Separation alone doesn't guarantee deliverability.

Key considerations

  • Subdomain vs. Domain: Decide on level of separation needed (subdomain vs. separate domain).
  • Warming Schedule: Plan a domain/IP warming schedule.
  • Content Quality: Ensure outreach content is engaging and compliant.
  • Sending Practices: Adhere to best practices for sending volume, frequency, and list management.
  • Monitoring: Monitor sender reputation and deliverability metrics.

What email marketers say
11Marketer opinions

The prevailing recommendation is to separate prospecting outreach emails from your primary domain to protect sender reputation. This separation can be achieved through subdomains or completely separate domains. While subdomains offer some level of protection, separate domains provide better isolation. Warming up any new domain or subdomain before large-scale sending is essential. It's also crucial to note that simply using a separate domain doesn't guarantee deliverability; the content and sending practices must still avoid being flagged as spam. Damaging your primary domain's reputation can have significant negative impacts on your overall email communication.

Key opinions

  • Protect Reputation: Separating outreach emails protects the main domain's reputation.
  • Subdomain vs Domain: Separate domains offer better isolation than subdomains, but either is better than nothing.
  • Warming Required: New domains/subdomains need warming up before large sends.
  • Not a Guaranteed Fix: Separation alone doesn't guarantee deliverability; avoid spam triggers.
  • Reputation Impact: Damaged reputation impacts all email streams.

Key considerations

  • Volume: Assess your cold email sending volume. High volumes necessitate more robust separation.
  • Content Quality: Ensure outreach content is relevant and engaging to avoid spam flags.
  • Warming Strategy: Develop a plan to gradually warm up your sending domain or subdomain.
  • Monitoring: Continuously monitor sender reputation and deliverability metrics.
  • Compliance: Ensure compliance with all applicable email marketing regulations.
Marketer view

Email marketer from Sendinblue shares that using a subdomain for cold outreach is good for protecting your main domain. They advise warming up the subdomain slowly before large scale sending.

September 2021 - Sendinblue
Marketer view

Email marketer from WebHostingTalk shares that it's always best to separate domains to keep main domain reputation pristine. They suggest using a completely different domain that has no association with your main company.

July 2021 - WebHostingTalk
Marketer view

Email marketer from Neil Patel shares that separating your cold outreach from your main domain is critical to protect your sender reputation. If you damage the reputation of the primary domain, it can harm all email communication, including important business correspondence.

February 2022 - Neil Patel
Marketer view

Marketer from Email Geeks recommends separating outreach activities by using a subdomain to protect the main domain's reputation.

October 2024 - Email Geeks
Marketer view

Email marketer from SuperOffice responds that using a separate domain for prospecting emails helps keep the main domain's reputation clean. If there are deliverability issues with the outreach domain, it will not affect other email streams.

December 2021 - SuperOffice
Marketer view

Email marketer from Hunter.io shares that sending cold emails from a separate domain is best practice. They say that the aim is to protect your primary domain’s deliverability and credibility.

July 2021 - Hunter.io
Marketer view

Email marketer from Woodpecker.co responds that for cold email outreach, using a separate domain or subdomain is highly recommended to safeguard your primary domain's reputation. This prevents potential damage from affecting your regular email communications.

August 2024 - Woodpecker.co
Marketer view

Marketer from Email Geeks warns that a separate domain isn't a guaranteed fix if the outreach is still considered spam.

October 2023 - Email Geeks
Marketer view

Email marketer from Mailjet explains that using a dedicated subdomain or separate domain for transactional or marketing emails can help isolate your sender reputation. If one domain faces deliverability issues, it won't affect the others.

December 2021 - Mailjet
Marketer view

Email marketer from Reddit explains that using a separate domain for cold outreach protects your primary domain's reputation. They also suggest warming up your domain and limiting the number of daily emails sent.

September 2023 - Reddit
Marketer view

Email marketer from Gmass recommends using a completely separate domain name and email address for cold email outreach. You shouldn't use a subdomain of your main website if you're sending a large volume of cold emails, as it can still impact your main domain's reputation.

November 2024 - Gmass

What the experts say
5Expert opinions

The consensus is that using a separate domain for prospecting outreach emails is crucial for protecting your primary domain's sender reputation. Outreach, especially cold outreach, is often viewed as spam and can lead to deliverability problems, potentially impacting opt-in emails and even corporate communications. Isolating outreach activities to a separate domain prevents negative impacts on your main domain. Starting slow and warming up new IPs or domains is also recommended to build a positive sender reputation.

Key opinions

  • Reputation Protection: A separate domain protects the primary domain from negative impacts of outreach.
  • Potential Damage: Outreach can damage domain reputation, affecting deliverability.
  • Isolation: Isolating outreach prevents problems impacting main business communications.
  • Warming Up: New domains/IPs need to be warmed up gradually.

Key considerations

  • Content Quality: Ensure outreach content is not perceived as spam.
  • Warming Strategy: Plan a strategy to gradually increase sending volume on new domains/IPs.
  • Source: Utilize dedicated source for sending so as to not affect the main domain.
Expert view

Expert from Email Geeks explains that outreach sales is often seen as spam and can damage domain reputation, potentially causing delivery problems for opt-in mail and even corporate communications. If a company insists on outreach, separating it onto a different domain is crucial to protect other email streams.

April 2022 - Email Geeks
Expert view

Expert from Spamresource explains that for cold outreach, using a separate domain is crucial to protect your primary domain's reputation. Damaging your main domain can affect important business communications.

March 2022 - Spamresource
Expert view

Expert from Word to the Wise recommends sending email from a new IP address or domain, you should start slow. The best way to warm up your IPs and domains is to start by sending small volumes of messages to your most engaged subscribers.

April 2024 - Word to the Wise
Expert view

Expert from Email Geeks suggests isolating sales outreach to its own domain and vendor as a good practice, even with low volumes. One intensely annoyed recipient can cause deliverability issues with corporate domains.

March 2021 - Email Geeks
Expert view

Expert from Word to the Wise explains that using a separate domain for outreach helps protect your main domain's reputation. If your outreach activities negatively affect your sender reputation, it won't impact your primary business communications.

October 2023 - Word to the Wise

What the documentation says
4Technical articles

Technical documentation from Google, Microsoft, RFC Editor, and Spamhaus all emphasize the importance of maintaining a positive sender reputation for email deliverability. A common recommendation is to segregate email streams by using different domains or subdomains for different types of email, especially bulk or marketing emails. This separation helps isolate potential reputation damage, minimizing the risk of negatively impacting other email streams, such as transactional or corporate communications. Utilizing subdomains or separate domains allows for easier sender identification and overall reputation management.

Key findings

  • Reputation Critical: Positive sender reputation is crucial for deliverability.
  • Segregation Recommended: Separate domains/subdomains for different email types is best practice.
  • Damage Isolation: Separation isolates reputation damage from bulk/marketing sends.
  • Reputation Management: Facilitates easier sender identification and reputation management.

Key considerations

  • Email Types: Determine the various email types you send (transactional, marketing, etc.).
  • Infrastructure: Establish separate sending infrastructures (domains/subdomains) for each type.
  • Monitoring: Monitor the reputation of each sending infrastructure independently.
  • Authentication: Properly configure authentication methods (SPF, DKIM, DMARC) for each sending infrastructure.
Technical article

Documentation from Google explains that maintaining a positive sender reputation is critical for email delivery. They recommend using a separate domain or subdomain for bulk sending to isolate any reputation damage from affecting important email streams.

May 2024 - Google Workspace Admin Help
Technical article

Documentation from Microsoft shares that using different domains or subdomains for different types of email (transactional, marketing, etc.) can help manage and protect your overall sender reputation. This segregation minimizes the risk of negative impacts from one email stream affecting others.

June 2022 - Microsoft Learn
Technical article

Documentation from Spamhaus explains that one best practice is to separate sending infrastructures based on email type. They say this practice enables you to isolate the potential impact of one type of email program from another.

December 2024 - Spamhaus
Technical article

Documentation from RFC Editor details that using subdomains or separate domains helps maintain sender identification. This segregation allows for easier reputation management and isolation of email streams, as outlined in standards like Sender ID.

March 2022 - RFC-Editor