How to troubleshoot Orange.fr bounces (SMTP greeting failed) in Klaviyo?

Key findings

• Early rejection: The "SMTP greeting failed" error means the receiving server, in this case Orange.fr, is refusing the connection right after the initial EHLO/HELO command.
• Generic EHLO: A generic EHLO string, such as kl-203-16-2.kmta.shared.klaviyomail.com, does not identify your specific sending domain, making it difficult for the receiving ISP to determine your sender reputation at this early stage.
• Shared IP impact: When using a shared IP address, issues like excessive sending by other users can negatively impact the IP's reputation, leading to blocklisting or rejection for all senders on that IP, even if your own sending practices are good. Learn more about bounce spikes on French ISPs.
• ISP specific requirements: Orange.fr, like many ISPs, has specific requirements for simultaneous connections and sending patterns that may not be universally implemented by email service providers (ESPs), contributing to greeting failures. This is detailed in their postmaster guidelines.

Key considerations

• ESP investigation: Your ESP, Klaviyo in this instance, needs to investigate the specific EHLO string and the overall reputation of their shared IPs being used for your sends to Orange.fr.
• Identify shared IP influence: Check if other senders on your shared IP are causing issues. Tools exist that can show you the overall health of your shared IP. You can investigate a shared IP's performance on the SenderScore platform.
• Orange.fr postmaster contact: Directly engage with Orange.fr's postmaster team via their official contact form for guidance on delivery issues, rather than using general abuse email addresses.
• Throttling and sending patterns: While batch sending might seem like a solution for bulk campaigns, "greeting failed" errors in transactional emails (like welcome series) suggest a deeper issue than just overall volume. It implies an immediate reputation or policy block.
• Deliverability assessment: Conduct a comprehensive deliverability assessment to understand why your emails are encountering high soft bounce rates, including those resulting from SMTP greeting failures.

Key opinions

• Frustration with generic greetings: Marketers express confusion and concern when their email platform uses generic EHLO strings that do not reflect their brand, potentially leading to identity issues at the receiving server.
• Shared IP concerns: A common fear among marketers on shared IPs is that the actions of other users could negatively affect their own deliverability, even if their sending practices are optimal.
• Klaviyo's role: Marketers often look to their ESP, like Klaviyo, for answers, as they typically do not have direct control over the underlying SMTP connection parameters or IP reputation management.
• Bounce rate impact: High bounce rates, including those from SMTP greeting failures, are a major concern as they directly impact campaign performance and sender reputation metrics. Klaviyo's support pages provide resources for decreasing bounce rates.

Key considerations

• Escalating with ESP support: Marketers should persist in escalating bounce issues to their ESP's specialized deliverability teams, providing detailed context and specific error messages.
• Understanding bounce types: Differentiating between soft bounces (like greeting failed) and hard bounces is crucial for appropriate list hygiene and suppression strategies. Klaviyo explains what a bounce-back email is.
• Proactive monitoring: While direct control might be limited on shared IPs, understanding how to monitor overall IP reputation and deliverability metrics remains important.
• Compliance with ISP guidelines: Marketers should familiarize themselves with major ISP guidelines, especially for large mailbox providers like Orange.fr, which often have specific requirements for email delivery. We have a guide on what to do when Orange.fr has issues.

Key opinions

• Connection stage failure: Experts confirm that a "greeting failed" error means the problem occurs at the very first step of the SMTP transaction, where the sending server attempts to introduce itself to the receiving server.
• IP-based trust: At the greeting stage, receiving servers primarily rely on the sending IP's reputation and its associated rDNS and EHLO string to decide whether to accept the connection.
• Lack of sender identity: If the EHLO string is generic and not tied to the sender's specific domain, the receiving ISP has no way to associate the incoming mail with a known, trusted sender at this critical initial phase.
• ESP's responsibility: Because the issue is at the IP and EHLO level, experts emphasize that the ESP (Klaviyo) is responsible for managing these aspects, especially on shared IPs, as clients generally lack direct control. This also ties into why emails to Orange.fr might fail.

Key considerations

• Reverse DNS and EHLO alignment: Ensure the EHLO hostname has a proper rDNS record that aligns with the sending IP, which helps in establishing initial trust with receiving mail servers.
• Monitoring shared IP reputation: Regularly check the reputation of shared IPs used by your ESP. Services like SenderScore can provide insights into the health of an IP, although direct action is limited for the client. This is crucial for understanding unclassified soft bounces from Orange.fr.
• Engagement with ESP deliverability: Maintain open communication with your ESP's deliverability team to understand their strategies for managing shared IP reputation and adhering to ISP-specific sending policies.
• Orange.fr specific policies: Be aware that French ISPs like Orange.fr may have stringent or unique requirements regarding connection limits and sending patterns that ESPs must accommodate. The Orange.fr postmaster website provides details on these delivery guidelines.

Key findings

• SMTP protocol fundamentals: The SMTP protocol dictates that an email transaction begins with a connection, followed by the HELO or EHLO command from the sender, which serves to identify itself to the receiver.
• Klaviyo's bounce categorization: Klaviyo's documentation often categorizes "greeting failed" as a soft bounce, indicating a temporary issue that may resolve, but persistent failures suggest deeper, unresolved problems.
• Authentication importance: While not directly at the greeting stage, proper email authentication (SPF, DKIM, DMARC) is crucial for downstream trust and helps ISPs differentiate legitimate mail, reducing the likelihood of early rejections on shared IPs.
• ISP postmaster guidelines: ISPs like Orange.fr provide specific postmaster pages detailing best practices, acceptable sending rates, and error codes to guide senders in achieving optimal deliverability.

Key considerations

• Regular bounce analysis: Continuously analyze bounce reports within Klaviyo to identify patterns, such as recurring "SMTP greeting failed" errors to specific ISPs, which can indicate persistent issues with Orange.fr.
• Reviewing ESP shared IP policies: Understand Klaviyo's approach to shared IP management, including how they monitor and mitigate risks from other senders, which can impact your deliverability to Orange.fr.
• Ensuring proper authentication: Verify that your SPF, DKIM, and DMARC records are correctly configured in Klaviyo to align your sending domain with the sending infrastructure, a key factor for trust. For more information, read our guide on troubleshooting DMARC, SPF, and DKIM setup.
• Consulting ISP postmaster sites: Regularly check the postmaster sites of major ISPs, particularly those causing significant bounces (like Orange.fr), for any updated policies or recommendations. You can find their guidelines on the Orange Postmaster site.