Summary
Email deliverability is complex and impacted by several interconnected factors. Subdomain practices significantly influence the parent domain's reputation, as mailbox providers often link them. While not the primary cause, technical configurations like SPF and DMARC are vital for preventing spoofing and ensuring proper authentication across both domains and subdomains. Deliverability issues often stem from how recipients engage with emails (or don't), with low engagement rates being a significant problem. Sending unsolicited mail to spam traps has severe consequences. Consistent email sending and managing shared IP addresses are also important for maintaining a positive sender reputation. Finally, the quality and relevance of your email content directly impact deliverability.
Key findings
- Subdomain Impact: Subdomain practices affect the parent domain's reputation, so monitoring and management are vital.
- Engagement is Key: Low engagement rates (low opens, clicks) are a primary driver of deliverability issues.
- Authentication Matters: Proper SPF, DKIM, and DMARC configuration is critical for both domains and subdomains to prevent spoofing.
- Spam Traps are Deadly: Sending emails to spam traps has a severe and immediate negative impact on deliverability.
- Consistency Counts: Consistent sending patterns, even in small volumes, improve sender reputation.
- Sender Reputation: Subdomain activities can be tied back to the parent domain causing damage if they are sending unsolicited emails.
- Content quality: Content quality is an important factor for deliverability.
Key considerations
- Subdomain Monitoring: Implement robust monitoring of subdomain sending practices to identify and address issues quickly.
- Improve Engagement: Focus on creating engaging content that recipients want to receive to improve open and click-through rates.
- Authenticate Properly: Ensure correct SPF, DKIM, and DMARC configuration for both your domain and all subdomains.
- Practice List Hygiene: Regularly clean your email lists to remove inactive addresses and avoid hitting spam traps.
- Maintain Consistency: Establish a consistent email sending schedule and avoid sudden spikes in volume.
- Content Marketing: Create high quality content that email recipients want to read and engage with.
What email marketers say
9 marketer opinions
Several factors influence email deliverability, and subdomain practices can impact the parent domain's reputation. Maintaining good sender reputation across all subdomains is essential, as mailbox providers can link negative practices to the overall brand. Sending spam from a subdomain can negatively affect the parent domain's reputation. While subdomains operate somewhat independently, mailbox providers consider the reputation of all parts of the domain. Subdomain segmentation can help isolate reputation issues. Engagement rates (opens and clicks) are crucial, as low engagement leads to deliverability problems. Newer domains might face deliverability challenges due to a lack of established reputation, requiring a gradual increase in sending volume. Hitting spam traps severely harms deliverability. Good email content is also key to high engagement.
Key opinions
- Sender Reputation: Maintaining a good sender reputation is crucial for email deliverability.
- Subdomain Impact: Negative practices on subdomains can affect the parent domain's reputation.
- Engagement Rates: Low engagement rates (opens, clicks) are a primary cause of deliverability issues.
- New Domains: Newer domains may have lower deliverability due to a lack of established reputation.
- Spam Traps: Sending emails to spam traps negatively impacts deliverability.
- Content Quality: Email content quality also impacts deliverability.
Key considerations
- Subdomain Management: Implement strategies to manage and monitor the sending practices of all subdomains.
- Segmentation: Consider segmenting sending across different subdomains to isolate reputation issues.
- Engagement Monitoring: Monitor and improve engagement rates (opens, clicks) to improve deliverability.
- Gradual Ramp-Up: For new domains, gradually increase sending volume over time to build a positive reputation.
- List Hygiene: Implement practices to avoid sending emails to spam traps, such as regular list cleaning.
Marketer view
Email marketer from NeilPatel.com shares that factors impacting email deliverability include sender reputation, email authentication (SPF, DKIM, DMARC), content quality, engagement rates, and blacklist status.
14 Nov 2021 - NeilPatel.com
Marketer view
Email marketer from ActiveCampaign answers question about sender reputation. Sender reputation is so important to email deliverability, and it can be affected by many things.
13 Jun 2025 - ActiveCampaign
What the experts say
6 expert opinions
Email deliverability is influenced by various factors. Mailbox providers connect subdomains and root domains, and significant subdomain issues can negatively impact the parent domain. Deliverability problems often stem from how recipients interact with emails, not just technical configurations like DMARC or SPF. A limited number of public blocklists significantly affect delivery. Consistent email sending, even in small volumes, is beneficial. Shared IP addresses can lead to deliverability problems due to other senders' actions. Sending wanted, relevant emails that drive user engagement are also key.
Key opinions
- Subdomain Connection: Mailbox providers link subdomains and root domains, meaning issues in subdomains can affect the parent domain's reputation.
- User Interaction: Recipient interaction with emails is a primary factor influencing deliverability.
- Blocklist Impact: Only a few public blocklists significantly impact email delivery.
- Consistent Sending: Regular email sending, even in small amounts, is better for sender reputation.
- Shared IP Risks: Using a shared IP address can expose you to deliverability issues caused by other senders.
- Email Content Quality: Ensure you send emails that are wanted and relevant to the users.
Key considerations
- Monitor Subdomains: Carefully monitor the sending practices of subdomains to prevent negative impacts on the parent domain.
- Focus on Engagement: Prioritize strategies to improve user engagement with your emails.
- Review Blocklists: Regularly check your domain against the most influential public blocklists.
- Maintain Consistency: Establish a consistent email sending schedule.
- Assess IP Address: Evaluate whether a shared IP address is appropriate for your sending volume and reputation needs, and be aware of the other emails being sent on that ip.
Expert view
Expert from Email Geeks explains that only a half dozen public blocklists are widely used and affect delivery, while another dozen indicate some bad traffic.
2 Jul 2023 - Email Geeks
Expert view
Expert from Spam Resource explains that if you're using a shared IP address, your deliverability can be affected by other senders on that IP. They recommend monitoring your IP reputation and considering a dedicated IP if problems arise.
21 Jun 2023 - Spam Resource
What the documentation says
4 technical articles
Email deliverability is affected by subdomain practices and requires proper configuration. Subdomains inherit reputation, meaning poor practices on a subdomain can negatively impact the parent domain. SPF records are crucial for subdomains to prevent spoofing, and an empty record should be set if no emails are sent. DMARC policies, including subdomain policies, should be implemented. General email deliverability improvements are beneficial to ensure proper email infrastructure is maintained.
Key findings
- Reputation Inheritance: Subdomains inherit some reputation from the parent domain.
- SPF Importance: SPF records are necessary for subdomains to prevent email spoofing.
- DMARC Policies: DMARC policies can be applied to subdomains with distinct policies from the parent domain.
- General Email Infrastructure: Ensure email infrastructure is setup correctly to ensure deliverability.
Key considerations
- Monitor Subdomains: Actively monitor the sending practices of subdomains.
- Implement SPF: Create SPF records for all subdomains that send mail, or set an empty record if they don't.
- Configure DMARC: Implement DMARC policies, including subdomain policies, based on organizational needs.
- Deliverability improvements: Improve email deliverability practices to ensure emails reach their recipient.
Technical article
Documentation from Google Workspace Admin Help explains that subdomains inherit some reputation from the parent domain, and poor sending practices on a subdomain can negatively impact the parent domain's reputation. They strongly recommend monitoring subdomain sending practices.
14 Aug 2022 - Google Workspace Admin Help
Technical article
Documentation from DMARC.org explains that DMARC policies can be applied to subdomains via the 'sp' tag in the DMARC record, allowing organizations to set different policies for subdomains than the parent domain.
31 Oct 2021 - DMARC.org
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