How do I setup a subdomain for email sending with Klaviyo?

Key findings

• No direct IP assignment: For email sending subdomains, especially when using an ESP like Klaviyo, you typically don't need to manually assign an IP address (e.g., via an A record) to the subdomain itself.
• DNS records are primary: The setup primarily involves adding or modifying DNS records (like SPF, DKIM, and CNAMEs) in your domain's DNS provider.
• Klaviyo's guidance: Klaviyo offers an authentication wizard that provides the specific DNS records you need to add to your DNS host.
• DMARC coverage: Your primary domain's DMARC policy typically automatically covers all subdomains, making a separate DMARC record for the subdomain usually unnecessary unless there are specific, advanced requirements.

Key considerations

• CNAMEs for authentication and branding: Klaviyo typically uses CNAME records to verify your domain, manage SPF and DKIM authentication, and handle custom link branding. These CNAMEs point to Klaviyo's infrastructure.
• PTR records for dedicated IPs: If you are using a dedicated IP address (which Klaviyo can provide for high-volume senders), you might need an A record for the subdomain to support a custom branded PTR (reverse DNS) entry for that IP. This is an advanced step often handled with Klaviyo's support.
• Distinct from web hosting: An email sending subdomain serves a different purpose than a web hosting subdomain. Its primary role is to isolate your email sending reputation from your main website.
• SSL for branded CNAMEs: While Klaviyo handles much of the DNS setup, configuring SSL for custom branded CNAMEs (for secure tracking links) might be an additional step that needs to be managed separately, often with your DNS provider or CDN like Cloudflare. For more details, consult Klaviyo's official documentation on branded sending domains.

Key opinions

• Simplicity of ESP setup: Many marketers find that Klaviyo's (and other ESPs') setup wizards greatly simplify the process, guiding them through the necessary DNS configurations.
• Focus on DNS records: The primary technical task is consistently identified as adding or modifying SPF, DKIM, and CNAME records, rather than IP configuration.
• Subdomain for reputation management: Marketers appreciate using a subdomain to protect their main domain's reputation from potential email delivery issues.
• Verification challenges: Occasionally, marketers encounter issues with TXT records not verifying, requiring careful troubleshooting of DNS propagation and record accuracy.

Key considerations

• Adhering to Klaviyo's guide: Following Klaviyo's specific setup instructions is crucial, as the exact records and steps can vary.
• DNS provider variations: The interface and specific steps for adding DNS records can differ significantly between DNS providers (e.g., Cloudflare, GoDaddy), requiring familiarity with your chosen provider.
• Consistent link branding: Setting up a subdomain correctly is vital for maintaining consistent and professional link branding in emails, which contributes to recipient trust.
• Deliverability impact: Proper subdomain setup, including correct SPF, DKIM, and DMARC authentication, directly impacts email deliverability and inbox placement.

Key opinions

• Synthetic subdomain creation: Experts confirm that for email, a subdomain is often created 'synthetically' by establishing SPF and DKIM records in DNS, without needing a direct A record to an IP.
• CNAMEs are standard: Klaviyo and other ESPs typically use CNAME records to manage critical authentication (SPF, DKIM) and custom link branding for the subdomain.
• DMARC inherited: DMARC policies are generally inherited by all subdomains under the primary domain, meaning a separate DMARC record for the email sending subdomain isn't required unless for specific exceptions.
• A record for PTR/rDNS: An A record might be necessary for the subdomain to support a custom branded PTR (reverse DNS) for a dedicated IP address, which is crucial for certain deliverability aspects.

Key considerations

• Leverage ESP wizards: Experts advise relying on the ESP's sending domain authentication wizard, as it should walk you through most of the required steps automatically.
• SSL for custom CNAMEs: Be aware that the wizard might not cover the setup of SSL certificates for custom branded CNAMEs, which might require manual configuration with your DNS provider.
• Delegation of authority: It is common for ESPs to require you to delegate authority for the subdomain to them through DNS records, allowing them to manage sending on your behalf.
• Beyond basic setup: While the wizard handles the basics, more complex scenarios, like using dedicated IPs, may involve additional steps or direct coordination with Klaviyo support. You can learn more about how to set up email subdomains in general.

Key findings

• Branded sending subdomain requirement: Klaviyo explicitly states that when setting a dedicated sending domain, users will need to add a subdomain.
• Klaviyo generates records: The platform is designed to generate the necessary DNS records (typically CNAMEs for SPF, DKIM, and tracking) for you.
• DMARC alignment: Documentation highlights that for DMARC compliance, the domain in your friendly-from email address must align with your sending subdomain.
• Step-by-step guidance: Official guides walk users through clicking on their company name, selecting settings, choosing domains, and adding the new branded sending domain.

Key considerations

• DNS provider selection: Within Klaviyo, you're prompted to select your DNS provider from a dropdown menu, which then customizes the instructions for adding the DNS records.
• Record verification: After adding the records to your DNS host, Klaviyo requires a verification step within their platform to confirm the records are correctly configured and propagated.
• Importance of authentication: The documentation consistently emphasizes that proper setup of SPF, DKIM, and DMARC is fundamental for email deliverability and ensuring messages reach the inbox rather than the spam folder.
• Troubleshooting common issues: Guides often include sections for troubleshooting common problems, such as TXT records not verifying, which can be due to propagation delays or incorrect entry. You can also explore troubleshooting DMARC, SPF, and DKIM setup issues.