How do I integrate an external SMTP with Klaviyo?

Key findings

• Direct SMTP integration: Klaviyo does not natively support connecting an external SMTP server for sending emails through their platform.
• Purpose-built infrastructure: Klaviyo manages its own email sending infrastructure, focusing on delivering marketing and transactional emails directly from its system.
• Branded sending domain: The recommended approach for maintaining brand identity and improving deliverability with Klaviyo is to set up a branded sending domain.
• Email authentication: Proper configuration of SPF, DKIM, and DMARC records is crucial when using Klaviyo to ensure your emails are authenticated and reach the inbox. Our guide on setting up SPF and DKIM can provide more details.

Key considerations

• Deliverability: While you cannot use an external SMTP, Klaviyo's internal infrastructure is optimized for deliverability. Focus on maintaining a healthy sender reputation by sending relevant content to engaged subscribers.
• API for transactional emails: For transactional emails that require specific SMTP configurations, consider if Klaviyo's transactional email API meets your needs, or explore using dedicated transactional email services alongside Klaviyo.
• Domain alignment: Ensure your sending domain is properly aligned and authenticated within Klaviyo to avoid deliverability issues.
• Support resources: Always consult Klaviyo's official support documentation for the most up-to-date information on their capabilities and recommended setups.

Key opinions

• No direct SMTP option: Many marketers confirm that Klaviyo does not offer a direct feature to connect an external SMTP server for email sending.
• Leverage branded domains: The focus should be on setting up a branded sending domain within Klaviyo to ensure emails appear from your domain and improve trust.
• API for specific needs: For transactional or highly customized email flows, marketers might explore Klaviyo's API or use a separate transactional email service, as detailed in our guide on managing transactional emails through your own SMTP.
• Platform limitations: Some users expressed confusion regarding this limitation, often expecting more direct control over SMTP settings as they might have with other platforms.

Key considerations

• Deliverability impact: Instead of external SMTP, focus on optimizing your Klaviyo setup for deliverability, including proper SPF, DKIM, and DMARC configurations.
• Workarounds: If a specific SMTP service is critical, marketers often use integration platforms to bridge Klaviyo with other email services indirectly, as seen with Zapier's integration with SMTP.com.
• Alternative sending solutions: Consider if a separate email sending solution like SendGrid, Mailgun, or Mandrill is needed for specific email types outside of Klaviyo's marketing flows.
• Integration complexity: Adding layers of external SMTPs or third-party integrators can increase complexity and potential points of failure compared to using a platform's native sending capabilities.

Key opinions

• Architectural design: Experts note that Klaviyo's platform architecture typically doesn't allow for external SMTP integrations, as it's built to manage sending internally for performance and control.
• Focus on authentication: Instead of external SMTP, the critical aspect is ensuring robust email authentication, including SPF, DKIM, and DMARC, for the domain sending through Klaviyo. Learn more about DMARC, SPF, and DKIM.
• Transactional vs. marketing: For transactional emails that truly require a separate SMTP service, it's often better to use specialized providers like SendGrid or Mailgun, as Klaviyo is primarily a marketing platform.
• Sender reputation: Maintaining a strong sender reputation is paramount. Klaviyo's internal infrastructure helps manage this, provided users adhere to best practices like list hygiene and engagement. Discover why your emails fail and how to improve deliverability.

Key considerations

• Compliance and deliverability: Using Klaviyo's internal sending system with a properly configured branded domain ensures compliance and leverages their expertise in deliverability. Attempting to force an external SMTP might introduce deliverability issues if not handled meticulously.
• Alternative methods: If a custom SMTP is absolutely necessary, consider using a separate system for transactional emails and integrate data with Klaviyo via API, rather than sending through Klaviyo's interface. This is common for configuring external SMTP providers for specific applications.
• Monitoring and troubleshooting: Klaviyo provides tools for monitoring email performance. If you were to use an external SMTP, you'd need separate monitoring and troubleshooting systems, adding complexity to your email program.

Key findings

• Klaviyo's official stance: Klaviyo documentation guides users on setting up branded sending domains and authenticating them, which is their primary method for controlling sender identity, as stated in their article on setting up a branded sending domain.
• No direct SMTP access: Documentation generally does not provide steps for connecting an external SMTP server to Klaviyo, indicating this is not a supported integration path.
• Email authentication importance: Klaviyo's help center emphasizes understanding email authentication, including DMARC compliance, by connecting a branded sending domain that matches the root domain in your friendly-from address.
• External SMTP in other contexts: Documentation from other platforms, like Auth0, often provides detailed instructions on how to configure external SMTP email providers for their services, highlighting a different approach.

Key considerations

• Adherence to platform guidelines: Always follow Klaviyo's official guidelines for email sending and domain setup to ensure optimal performance and avoid deliverability issues. This is especially true when setting up SPF, DKIM, and DMARC for Klaviyo.
• DMARC compliance: Documentation stresses the necessity of DMARC compliance, which requires connecting a branded sending domain. This ensures that your email's 'From' address aligns with your authenticated domain.
• API for custom needs: If you have unique sending requirements, refer to Klaviyo's API documentation. This is where you would find ways to programmatically send emails, potentially integrating with other services, rather than a direct SMTP connection.
• Troubleshooting: When issues arise, consult Klaviyo's help articles on troubleshooting, as they are tailored to their specific sending environment and authentication methods.