What is the best practice for warming up a new client's email list in Klaviyo?

Key findings

• Gradual ramp-up: Start with smaller volumes of email sends and gradually increase over time, especially when using a new platform like Klaviyo.
• List hygiene is paramount: Before sending, clean the list to remove bouncers, bots, and dormant addresses. Sending to an unengaged or old list can severely harm your sender reputation and lead to blocklists. For more information, see our guide on what an email blacklist is and how it works.
• Engagement-focused segmentation: Prioritize sending to the most engaged segments of your list, such as recent purchasers or active subscribers, to build positive engagement metrics.
• Initial welcome series: Begin with a non-promotional welcome series to introduce the brand and set expectations, rather than immediately pushing sales. This builds a relationship and helps establish positive engagement.
• Explicit opt-in: Even for existing customer lists, consider an email that invites them to explicitly opt-in to the newsletter or marketing program to ensure consent and reduce complaint rates. This is especially true for older lists, and can prevent emails from going to spam.

Key considerations

• List age: The older and more dormant the list, the higher the risk. For lists over a year old that have never been emailed, starting fresh with new opt-ins might be safer than trying to warm up the entire list.
• Data availability: Leverage any existing data, such as purchasing history, to create highly targeted segments for initial sends, as this can indicate higher engagement potential.
• Cadence and volume: There isn't a one-size-fits-all cadence. It's a gradual process of increasing volume to responsive segments, carefully monitoring engagement metrics and adjusting as needed. Avoid sending to the entire list of 30k after just one week.
• Unsubscribe visibility: Always make the unsubscribe link very easy to find. This helps minimize spam complaints, which are more damaging to sender reputation than unsubscribes.
• Monitoring: Continuously monitor your deliverability metrics, including open rates, click-through rates, bounce rates, and spam complaint rates, to adapt your warming strategy.

Key opinions

• List quality over quantity: It is crucial to ensure the email list is properly sourced and consists of genuinely interested subscribers. Sending to a list that is old or has never been emailed can lead to significant deliverability issues.
• Prioritize engaged segments: When beginning, it's best to send to the most engaged segments, such as recent purchasers. This helps build positive sender reputation from the start and can be integrated into your IP warming strategy.
• Slow and steady wins: The warming process should be viewed as a marathon, not a sprint. Gradually increasing volume to engaged recipients will yield better long-term results than attempting to send to the entire list too quickly.
• Relationship building first: Initial email flows should focus on introducing the brand and explaining how the recipient's email was acquired, rather than immediate sales pitches. This foundational engagement helps improve email deliverability.

Key considerations

• List cleaning: Even with an engaged audience, cleaning the list for inactive or invalid addresses before starting is a crucial step to maintain good deliverability.
• Leverage existing data: If purchasing history or other engagement data exists, use it to segment your list and identify the most active subscribers for initial sends.
• Avoid immediate large campaigns: After a week of flows, it's generally too soon to send campaigns to a 30k list that has never been emailed before, as this could trigger spam filters.
• Set proper expectations: Educate the client that warming is a long-term process, especially for a new sender on a new platform. The focus should be on building a positive sender reputation.

For further insights into setting up successful email campaigns, the Ultimate Guide to Klaviyo Best Practice offers valuable strategies for optimizing engagement and segmentation within the platform.

Key opinions

• Explicit consent is non-negotiable: Do not assume customers want marketing emails simply because they are existing clients. Actively invite them to opt-in to the newsletter or marketing program to ensure consent and avoid triggering complaints. For more on best practices, see how to warm up a new email sender address.
• Complaint prevention: Minimizing complaints is more important than avoiding unsubscribes. High complaint rates severely damage sender reputation, potentially leading to blocklists or emails being sent directly to spam.
• Transparency and easy opt-out: If a full opt-in process is not feasible, clearly introduce the brand and the purpose of the email, and provide a very easy-to-find unsubscribe link. This respects the recipient's choice.
• Engagement first, sales second: The initial focus should be on building a relationship and re-engaging the audience, especially if the list is older or unmailed. This helps in warming up an old email list.

Key considerations

• Respect for recipients: Treat customers with respect by only sending them mail they explicitly want. This approach maintains a positive sender reputation and prevents negative feedback.
• Long-term deliverability: Short-term gains from mass sending to an unengaged list are often outweighed by long-term damage to sender reputation. A slow, consent-driven warm-up fosters sustainable deliverability.
• Risk assessment: Consider the potential for triggering spam traps or high complaint rates if the list is questionable. These can severely impact future email performance on Klaviyo and other platforms.
• Client education: Educate the client on the risks of non-permission-based sending and the benefits of a proper warm-up strategy. This includes explaining the importance of using a strategic warming process in Klaviyo.

Key findings

• Sender reputation is key: The primary goal of warming is to establish a strong sender reputation, ensuring inbox providers view your emails favorably. This directly impacts email deliverability.
• Ramping up volume: Warming involves starting with smaller email volumes and gradually increasing them over time. This controlled approach signals legitimate sending behavior to ISPs.
• Guided warming process: Klaviyo can provide guidance on whether your campaign sending practices align with your current warming stage, helping you adjust as needed. You can read more about dedicated IP warm-up best practices.
• Deliverability monitoring: Understanding good email deliverability metrics and applying strategies to improve performance is part of the warming process. Monitoring is key to knowing when to increase send volume.

Key considerations

• Choosing the right process: Klaviyo offers different warming processes. Selecting the correct one based on your specific sending volume and list characteristics is crucial for success.
• Engagement optimization: Optimizing email content, subject lines, and segmentation to maximize engagement (opens, clicks) is vital during warming. High engagement signals positive sender behavior to ISPs.
• Subscriber consent: Klaviyo provides tools and APIs for managing subscriptions, such as signup forms and the Subscribe to List API. These should be utilized to ensure proper opt-in practices. This is a fundamental part of warming a new email sending domain.
• Gradual increase, not sudden burst: Never attempt to send to the full list (e.g., 30k contacts) after a short warming period. This abrupt increase in volume can trigger spam filters and damage sender reputation.

For a comprehensive overview of Klaviyo's guidance on establishing a strong sender reputation and being viewed favorably by inbox providers, refer to their article on understanding which warming process to use in Klaviyo.