Summary
Domain reputation in email sending is multifaceted, applying to both the primary domain and its subdomains (FQDNs). Subdomains offer a way to segment email traffic and protect the primary domain's reputation by isolating issues. While most of the time reputation follows the full domain, the sending reputation of a subdomain can influence the overall domain reputation, both positively and negatively. Consistent sending practices, good engagement metrics, and proper email authentication (SPF, DKIM, DMARC) across all domains and subdomains are crucial. ISPs may discard reputation information for low-volume subdomains. Newer subdomains require careful warm-up and continuous monitoring through feedback loops. DMARC policies applied to a domain also extend to its subdomains. Using subdomains strategically helps to control and manage your overall sending reputation.
Key findings
- FQDN Reputation: Reputation is associated with the Fully Qualified Domain Name (FQDN), encompassing both domain and subdomains.
- Reputation Influence: Subdomain sending practices can impact the overall domain reputation.
- Subdomain Segmentation: Subdomains can segment email traffic and isolate reputation risks.
- Authentication Importance: Proper email authentication (SPF, DKIM, DMARC) is essential across all sending domains.
- ISPs and Volume: ISPs may not track or value reputation for very low-volume subdomains.
- DMARC Policy: DMARC policies on the parent domain apply to subdomains as well.
- Reputation flow: Reputation flows up and down from subdomains to parent domain and vice versa
Key considerations
- Strategic Subdomain Use: Carefully plan your subdomain structure and usage to maximize reputation benefits.
- Consistent Practices: Maintain consistent and positive sending practices across all subdomains and the main domain.
- Email Authentication: Implement and maintain proper email authentication (SPF, DKIM, DMARC).
- Domain Warm-up: Warm up new subdomains gradually to build a good sending reputation.
- Reputation Monitoring: Monitor your domain and subdomain reputation using feedback loops and other tools.
What email marketers say
11 marketer opinions
Domain reputation in email sending is influenced by factors at both the domain and subdomain level. Subdomains can be used to segment email traffic, isolating reputation issues and protecting the main domain's reputation. However, ISPs may discard reputation data for low-volume subdomains. Authentication (SPF, DKIM, DMARC) is crucial for all domains and subdomains, and consistent sending practices with good engagement metrics contribute to a positive overall brand reputation. Newer subdomains require careful warm-up. Monitoring reputation through feedback loops is essential, especially when on shared IP addresses.
Key opinions
- Subdomain Segmentation: Using subdomains to separate email types (e.g., transactional vs. marketing) helps isolate reputation problems.
- ISPs and Volume: ISPs might ignore reputation data from subdomains with low sending volumes.
- Shared IP Impact: Shared IP addresses mean your reputation is partly determined by other users on the same IP.
- Authentication is Key: Proper authentication (SPF, DKIM, DMARC) is crucial for all domains and subdomains.
- Brand Reputation: Consistent sending practices and engagement contribute to overall brand reputation.
- Domain Reputation Flow: Reputation flows up and down and can affect subdomains and parent domains
Key considerations
- Warm-up: Newer subdomains need a gradual warm-up period to establish a positive reputation.
- Monitoring: Implement feedback loops to actively monitor domain and subdomain reputation.
- Engagement Metrics: Monitor engagement metrics (opens, clicks, complaints) to assess and improve reputation.
- Domain and Subdomain Strategy: Carefully plan how you are using domains and subdomains to control reputation flow
Marketer view
Email marketer from Email Geeks shares that ISPs may also throw away reputation information for subdomains that don't meet minimum volume thresholds.
8 Mar 2023 - Email Geeks
Marketer view
Email marketer from Litmus emphasizes the importance of proper email authentication (SPF, DKIM, DMARC) for all sending domains and subdomains. Correctly configured authentication helps ISPs verify your identity and improves deliverability.
15 Jan 2024 - Litmus
What the experts say
4 expert opinions
Domain reputation is complex, applying to both the entire domain and individual subdomains (FQDNs). While reputation is generally tied to the full domain, subdomains can have separate reputations, offering isolation for different email campaign types. Sending practices and engagement data across all subdomains influence the overall domain reputation.
Key opinions
- FQDN Reputation: Reputation applies to the Fully Qualified Domain Name (FQDN), which includes subdomains.
- Reputation Flow: Reputation exists at both the parent domain and subdomain level, with influence flowing between them.
- Subdomain Isolation: Subdomains can have independent reputations, allowing you to isolate different email types (e.g., transactional vs. marketing).
- Impact on Overall Domain: Sending practices on subdomains contribute to the overall reputation of the primary domain.
Key considerations
- Strategic Subdomain Use: Use subdomains strategically to separate email types and protect your primary domain's reputation.
- Consistent Practices: Maintain consistent sending practices and engagement data across all subdomains and the primary domain.
Expert view
Expert from Email Geeks explains that there is reputation on every FQDN and on the parent domain, and it flows up and down.
24 Sep 2023 - Email Geeks
Expert view
Expert from Word to the Wise explains that a FQDN's (Fully Qualified Domain Name) reputation is based on the sending practices associated with that specific domain name. They share that consistent sending practices and engagement data across your subdomains and overall domain affect your brand reputation.
12 Sep 2021 - Word to the Wise
What the documentation says
6 technical articles
Using subdomains in email sending can help protect the primary domain's reputation, although a poor subdomain reputation can negatively impact the overall domain. An FQDN uniquely identifies an internet host. Warming up new IPs and subdomains with gradually increasing sending volume is important. DMARC policies applied to a domain affect subdomains. Separating sending domains by email type isolates reputation risks.
Key findings
- Subdomain Protection: Subdomains can shield the primary domain from reputation damage.
- FQDN Definition: FQDNs specify the exact location in the domain name hierarchy.
- Negative Impact: Poor subdomain reputation can harm the primary domain.
- Gradual Warm-up: Warming up new IPs and subdomains gradually builds positive reputation.
- DMARC Impact: DMARC policies affect subdomains.
- Domain Separation: Isolating email types with subdomains minimizes reputation risks.
Key considerations
- Careful Monitoring: Monitor all subdomains to prevent negative impact on the primary domain.
- Proper Warm-up: Implement a gradual warm-up strategy for new subdomains.
- DMARC Configuration: Understand how DMARC policies interact with subdomains.
- Strategic Separation: Strategically use subdomains to isolate email types and protect your core domain reputation.
Technical article
Documentation from SparkPost mentions that when warming up a new IP address or subdomain, it's important to gradually increase sending volume to build a positive reputation with ISPs. FQDN reputation builds over time based on sending practices.
13 Apr 2024 - SparkPost
Technical article
Documentation from DMARC.org shares that DMARC policies applied to a domain can also affect subdomains. Understanding how these policies interact is critical for managing email authentication and reputation.
13 Jan 2022 - DMARC.org
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