Summary
Sharing an email sending domain with a partner, even if they are a trusted business associate, introduces significant deliverability risks. Your primary domain's reputation is a critical asset, and its health directly influences the inbox placement of all emails sent from it or its subdomains. When a partner uses a subdomain or even the primary domain for their own sending, their email practices can directly impact your sender reputation, potentially leading to your emails being flagged as spam or outright rejected by internet service providers (ISPs).
Key findings
- Shared reputation: Using the same parent domain means that email reputation is shared across all entities. Poor email practices by one party can harm the deliverability of all.
- Subdomain inheritance: Subdomains inherit a portion of the reputation from their parent domain, meaning a decline in the primary domain's reputation will impact subdomains, and vice versa.
- Blacklisting risk: If a partner engages in spammy behavior, the domain could be added to a blocklist or blacklist, affecting all legitimate sending from that domain or its subdomains.
- Authentication reliance: Reputation systems heavily rely on DKIM-signed domains and proper authentication (SPF, DMARC) for trusted sending.
Key considerations
- Dedicated domains: It is generally advised to avoid sharing sending domains entirely to prevent reputation contamination.
- Clear ownership: Ensure absolute clarity on who controls the DNS and sending infrastructure for any shared domains or subdomains.
- Monitor partners: If a shared setup is unavoidable, implement rigorous monitoring of the partner's email sending practices and domain reputation metrics.
- Proactive communication: Maintain open lines of communication with partners regarding email best practices and any potential deliverability issues.
What email marketers say
Email marketers often express concern over shared sending infrastructure, including domains, due to the inherent risk of one party's actions negatively impacting another's deliverability. The consensus typically leans towards maintaining as much control as possible over one's sender reputation, advocating for dedicated or branded sending domains to isolate their email program from external factors. The impact of shared domains can range from minor deliverability hiccups to severe blacklisting, underscoring the need for careful consideration when entering such arrangements.
Key opinions
- Shared risk: Marketers understand that sharing a domain means sharing its reputation, making them susceptible to a partner's poor sending habits.
- Control is key: Branded domains offer greater control over sender reputation, which is highly valued for stable deliverability.
- Brand impact: A damaged domain reputation can hurt brand trust and lead to emails landing in spam folders.
- Subdomain vulnerability: Negative engagement on a subdomain can extend its negative effects to the primary domain.
Key considerations
- Assess partnerships: Thoroughly evaluate the email sending practices of any partner before sharing a domain or subdomain.
- Separate sending: Using separate domains for different email platforms or partners helps isolate reputation.
- Consistent practices: All parties must adhere to best practices to maintain a good domain reputation.
- Proactive monitoring: Implement continuous monitoring of your domain's reputation to quickly detect and address any issues arising from shared usage.
Marketer from Email Geeks asks about the potential repercussions for their own email sending if a competitor is using a subdomain of their primary site for their own sending, wondering if their existing DNS records provide sufficient protection.
Marketer from NotifyVisitors explains that when other businesses use the same domain, their poor email practices can unfortunately harm the reputation of all users on that shared domain.
What the experts say
Deliverability experts consistently warn against sharing sending domains due to the high risk of reputation contamination. Their insights highlight that a primary domain's reputation is paramount and can significantly influence the deliverability of all related entities, including subdomains or partner senders. Technical configurations like DNS records and authentication protocols are crucial, but they cannot fully mitigate the risks posed by a partner's poor sending practices. Experts emphasize that transparency and control over all sending activity associated with a domain are vital for maintaining good sender reputation.
Key opinions
- Absolute control: Experts advise that one entity should have complete control over the DNS and sending practices for a domain to ensure consistent reputation.
- Avoid sharing: Sharing sending domains is strongly discouraged as it can lead to numerous deliverability issues and reputation damage.
- Primary domain impact: The reputation of the primary domain carries the most weight and can affect all associated subdomains or partners sending from it.
- Authentication importance: Proper domain authentication, including DKIM and DMARC, is crucial for reputation systems.
Key considerations
- DNS alignment: Ensure that DNS records are correctly configured and that all parties are properly authorized to send on behalf of the domain.
- Clear communication: Establish a clear understanding of sending responsibilities and best practices with any partners using your domain.
- Reputation monitoring: Actively monitor your domain's reputation and blocklist status to catch issues early.
- Dedicated IP ranges: For partners, consider using separate IP ranges and subdomains to minimize shared reputation risks.
Expert from Email Geeks suggests that a domain could be blacklisted if it's used for spam, although modern reputation systems tend to rely more heavily on DKIM-signed domains for trust.
Expert from SpamResource highlights that domain reputation is built on consistent, positive sending practices and can be easily damaged by actions like spam complaints or high bounce rates.
What the documentation says
Official documentation and technical guides from email service providers and industry bodies consistently underscore the risks associated with shared email sending domains. They often highlight that sender reputation is a composite score influenced by various factors, including the domain used for sending. The key takeaway from these resources is that while subdomains may offer some level of isolation, they are still linked to the primary domain's reputation. Therefore, any detrimental activity on a shared or sub-domain can cascade and impact the overall deliverability of the primary domain.
Key findings
- Reputation inheritance: Subdomains inherit aspects of the parent domain's reputation, making them susceptible to its overall health. A poor parent domain reputation can hurt subdomain deliverability.
- Shared risks: Poor email practices on a shared domain by any party can negatively affect all users of that domain.
- Control vs. sharing: Dedicated or branded domains provide more control over sender reputation compared to shared setups.
- Blocklisting: Being placed on an email blocklist due to a partner's actions can severely impact your own email deliverability.
Key considerations
- Isolate reputation: Where possible, use distinct sending domains or subdomains for different entities to isolate their reputations.
- Understand the factors influencing domain reputation to mitigate risks in shared environments.
- Authentication setup: Properly configure SPF, DKIM, and DMARC for all domains and subdomains.
- Monitoring practices: Actively monitor domain health and deliverability metrics for all associated sending entities.
Documentation from NotifyVisitors states that if other businesses using the same domain engage in poor email practices, it can significantly harm the reputation of all other users sharing that domain.
Documentation from Klaviyo Help Center explains that having a branded domain allows senders to exercise more control over their own sender reputation, which is beneficial for deliverability.
