Why are open rates so sensitive to ESP migration?

When you switch ESPs, your new sending domain on Klaviyo starts building a new sender reputation with ISPs. Even if your old ESP had a strong reputation, it doesn't directly transfer. ISPs observe your sending habits from the new platform, making the initial post-migration period critical for building trust, and any missteps can quickly lead to lower inbox placement.

How does warming up specifically help, and when does it go wrong?

Warming up helps establish a positive sender reputation by gradually increasing sending volume to engaged subscribers. It goes wrong when you rapidly increase volume or start sending to a large, unengaged portion of your list too soon, as this signals poor sending practices to ISPs, leading to filtering into spam folders and lower open rates.

What role do DMARC, SPF, and DKIM play in this issue?

DMARC, SPF, and DKIM are crucial email authentication protocols. They help verify that emails are legitimate and prevent spoofing. If these records are misconfigured or not fully implemented after a migration, ISPs are more likely to flag your emails as suspicious or spam, significantly impacting your deliverability and, consequently, your open rates.

Should I segment my list differently after migrating?

Yes, absolutely. After migrating, it's highly recommended to segment your list more aggressively, especially for campaigns. Focus on your most engaged subscribers initially to rebuild sender reputation on the new platform. Gradually re-engage less active segments with targeted campaigns rather than sending to your entire list at once, which can quickly harm your new reputation.

Can old email content hurt my new sender reputation?

Old or irrelevant email content, or content that significantly differs from what subscribers expect, can certainly hurt your new sender reputation. If recipients consistently ignore or mark your emails as spam due to unengaging content, ISPs will learn to filter your messages, regardless of your technical setup. Always strive for fresh, valuable, and relevant content.

Why did my email open rates suddenly drop after migrating to Klaviyo? - Troubleshooting - Email deliverability - Knowledge base

Migrating to a new email service provider (ESP) is a significant step, often anticipated to boost performance and streamline operations. However, it's not uncommon for businesses to experience unexpected challenges, such as a sudden and drastic drop in email open rates shortly after transitioning. This can be particularly alarming when you've invested time in a dedicated sending domain and initial warming efforts.

Imagine this scenario: you've moved from an ESP like Mailchimp to Klaviyo, completed a two to three-week warming-up phase with flows, and initially saw impressive open rates, perhaps over 50%, when sending to your most engaged subscribers. Then, after sending a few campaigns to your entire list, open rates plummet, dropping from a healthy 38-45% down to a concerning 11-15%. This decline can occur across multiple mailbox providers, impacting overall conversions and leaving you scrambling for solutions, especially with crucial sending periods like Black Friday and Cyber Monday looming.

The good news is that such drops, while frustrating, are often fixable. They typically stem from a combination of factors related to sender reputation, list management, technical configurations, and content strategy. Let's delve into the most common reasons your open rates might have dipped after migrating to Klaviyo and what steps you can take to recover and improve your email deliverability.

Sender reputation and list management

When you switch email service providers, even with a dedicated sending domain, your sender reputation essentially restarts or undergoes a significant recalibration with internet service providers (ISPs) and mailbox providers (MBPs). Your previous history with Mailchimp does not seamlessly transfer. This means that a new ESP (like Klaviyo) needs to build its own sending credibility on your behalf. Initially, you might see good open rates because you're sending to your most engaged audience during the warming period. However, this early success can mask underlying issues if the subsequent sending strategy is not carefully managed.

A common pitfall after warming up is immediately sending to your entire list, especially if a significant portion of it is unengaged. If 40% of your list hasn't shown recent engagement, sending campaigns to them through a new platform can quickly damage your fresh sender reputation. ISPs look for positive engagement metrics, and a sudden influx of emails to disengaged subscribers often leads to lower opens, higher ignored rates, and increased spam complaints, signaling to ISPs that your emails are not valuable, causing them to divert your mail to the spam folder. This is a common experience, as many discussions on platforms like the Klaviyo Community Forum highlight.

Effective list hygiene becomes paramount post-migration. If you have a substantial segment of unengaged subscribers, sending to them can be detrimental. It's crucial to continuously segment your list based on engagement and avoid sending to inactive contacts. Prioritizing your most active subscribers helps maintain a strong sender reputation, which is the cornerstone of good email deliverability. Maintaining a healthy list is essential for long-term success.

Avoid sending to unengaged segments

Sending email campaigns to a large portion of unengaged subscribers can severely harm your sender reputation. Mailbox providers interpret a lack of opens and clicks as disinterest or even spam, leading to future emails being filtered into the spam folder, thereby reducing your overall deliverability. Focus on re-engaging or suppressing inactive contacts to protect your sender score.

Technical configuration and authentication

While you've confirmed that SPF and DKIM are in place and DMARC is being set up, technical misconfigurations are a frequent cause of deliverability issues after an ESP migration. Even minor discrepancies in DNS records can lead to emails failing authentication checks, which can significantly impact inbox placement. It's vital to ensure these are correctly configured for your new sending domain within Klaviyo's specific requirements.

Another technical aspect is the potential for your sending domain or IP to land on a blocklist (or blacklist). While Gmail primarily uses its own internal blocklists, other mailbox providers widely reference public and private blacklists. A sudden surge in complaints or bounces from your new sending domain could trigger a listing. Regular monitoring for blocklist presence is a crucial part of maintaining strong email deliverability.

It's also worth noting that different ESPs can have varying methods for reporting open rates. Apple's Mail Privacy Protection (MPP) further complicates open rate metrics by pre-fetching images, which can inflate reported opens. While you've checked for clipping issues, it's possible Klaviyo's reporting methodology, or its interaction with MPP, differs from your previous ESP, leading to a perceived drop that might not reflect a true decline in inbox placement, but rather a more accurate, or at least different, measurement of actual human opens. This is less likely to cause such a drastic drop if conversions are also down, but it's a factor to consider.

ESP	Open rate calculation	Apple MPP impact
Mailchimp	Traditionally counts an open when the tracking pixel loads.	May show inflated opens due to automatic pixel loading for MPP users.
Klaviyo	Uses a similar pixel-based tracking method. Can sometimes experience clipping if code is bulky.	Also affected by MPP, potentially reporting higher opens than true human engagement.

Content and audience relevance

Even if your deliverability is technically sound, your content's relevance and appeal play a massive role in open rates. When migrating, consider if there have been any changes in content strategy, messaging, or email design. If the new campaigns use older or less engaging content, or if the messaging doesn't resonate as strongly with your audience as it used to, subscribers may simply choose not to open, or even worse, mark your emails as spam.

The transition to a new platform is a prime opportunity to re-evaluate your list segmentation strategy. While sending to your entire list might have seemed acceptable on your previous ESP, the new platform and your current sender reputation might not support it. Sending to a broad, unsegmented list, especially one with a high percentage of unengaged contacts, is a common reason emails end up in spam. Focusing campaigns on highly engaged segments can significantly improve your open rates and overall sender reputation.

To counteract declining engagement, implement A/B testing for subject lines, preview text, and calls to action. Personalization, dynamic content, and segment-specific messaging can help ensure your emails are more relevant to recipients, increasing the likelihood of opens and clicks. Ensure the content aligns with what your subscribers expect and value, especially during high-volume sending periods.

Mailchimp approach

Sending Habits: Consistent volume to the entire list, often 6-8 campaigns per month.
List Engagement: Open rates around 38-45% before the migration.
Content Strategy: Content that historically resonated with the audience.

Klaviyo transition strategy

Sending Habits: Initial warming period, then high volume to the 'whole list' including unengaged.
List Engagement: 40% of the list is unengaged, leading to diminished returns.
Content Strategy: Potential for content fatigue or lack of alignment with new platform's approach.

Diagnostic steps and recovery

To address the sudden drop, start by performing a thorough analysis of your email performance across different mailbox providers. Leverage tools like Google Postmaster Tools to identify any specific ISPs (like Gmail, Yahoo, Outlook) where your deliverability or reputation has taken the hardest hit. This will help you pinpoint where to focus your recovery efforts.

Next, implement aggressive list segmentation for your campaigns. Instead of sending to the entire list, prioritize your most engaged subscribers. This means targeting contacts who have opened or clicked your emails recently (e.g., in the last 30-60 days). Gradually expand to less engaged segments as your sender reputation stabilizes and improves. This strategic approach helps to recover domain reputation by demonstrating consistent positive engagement to ISPs.

Remember that improving email deliverability is a continuous process that requires patience. It's not always a quick fix, especially if reputation issues are involved. Consistent monitoring of your KPIs, adapting your sending strategy, and focusing on delivering highly relevant content will be key to long-term success on Klaviyo. Consider implementing re-engagement campaigns for inactive subscribers before fully reintegrating them into your main sending lists.

Key recovery strategies

Segment your list: Focus on sending to your most engaged subscribers first.
Run re-engagement campaigns: Try to reactivate dormant subscribers with targeted content.
Monitor performance closely: Track open rates, clicks, and spam complaints by domain.
A/B test subject lines: Optimize for maximum engagement and relevance.

Views from the trenches

Best practices

Focus on boosting engagement with active subscribers at affected mailbox providers.

Prioritize re-engagement campaigns for segments that are not currently opening emails.

Ensure all necessary email authentication records like SPF, DKIM, and DMARC are fully implemented.

Common pitfalls

Continuing to send campaigns to a large, unengaged portion of your email list.

Not accounting for potential differences in open rate reporting between email service providers.

Assuming previous sending habits will translate directly to a new email platform.

Expert tips

Investigate any content changes in new campaigns, as relevance significantly impacts open rates.

Verify that suppression and unsubscribe lists from the old provider were accurately imported.

Consider that a sudden drop might reveal pre-existing deliverability issues previously masked.

Expert view

Expert from Email Geeks says a sudden drop often indicates low engagement leading to spam folder placement, suggesting a focus on boosting engagement with affected mailbox providers. Verify DKIM is fully in place.

Nov 7, 2023 - Email Geeks

Marketer view

Marketer from Email Geeks says it is crucial to understand the engagement status of the 'whole list' and if it is varied.

Nov 7, 2023 - Email Geeks

Moving forward with Klaviyo

A sudden drop in email open rates after migrating to Klaviyo is a complex issue with multiple contributing factors. The key takeaways often revolve around the delicate balance of sender reputation, the integrity of your email list, correct technical configurations, and the continued relevance of your email content. It's rarely a single problem but rather a combination of these elements interacting within the new ESP environment.

Proactive monitoring, strategic list segmentation, and consistent efforts to engage your audience are essential for recovering and maintaining high open rates. By addressing these areas systematically, you can navigate the post-migration challenges and ensure your emails consistently reach their intended recipients, boosting your overall email marketing performance on Klaviyo.