What is 'panel data' in email deliverability, and how does it differ from seed testing?

Panel data refers to deliverability statistics gathered from a large, anonymous sample of actual subscriber inboxes. It provides a general overview of where your emails land for real users. Seed testing, on the other hand, involves sending emails to a predefined list of test email addresses across various ISPs to precisely see where your emails are placed (primary inbox, promotions, spam) and verify authentication.

Why would my inboxing rate be high but my open rate remain low?

A high inboxing rate with low open rates often indicates that your emails are reaching recipients' mailboxes, but not necessarily their primary or visible inboxes. They might be landing in secondary tabs (like Gmail's Promotions tab) or are simply not compelling enough to open due to factors like subject line, sender name, or content relevance. It's also possible bot activity inflates open rates.

How can I effectively re-permission users who may have been opted-in without consent?

To re-permission users, send a clear, concise email explaining the situation and asking them to explicitly confirm their desire to continue receiving your communications. Offer a strong incentive for re-opting in. Users who do not re-confirm should be removed from your marketing list to protect your sender reputation.

What are the risks of keeping unengaged subscribers on my email list?

Keeping unengaged subscribers can negatively impact your sender reputation. Low engagement signals to ISPs that your content isn't relevant, potentially leading to future emails being filtered to spam or blocked. It also increases the risk of hitting spam traps or generating higher spam complaints over time, which can damage your domain's health.

How often should I clean my email list to maintain deliverability?

The frequency of list cleaning depends on your sending volume and list churn, but a good practice is to identify and suppress unengaged subscribers every 3-6 months. For high-volume senders, continuous monitoring and automatic suppression of inactive contacts are recommended. Regular maintenance helps prevent issues like high soft bounce rates .

How should I handle users who may have been opted-in to marketing emails without consent, and how to diagnose low open rates with high inboxing rates? - Troubleshooting - Email deliverability - Knowledge base

Dealing with an email list where some users might have been opted-in without clear consent is a tricky situation. It's not just an ethical dilemma, but also a significant deliverability risk. Alongside this, facing low open rates despite high inboxing metrics can be incredibly perplexing. You see your emails being delivered, but they aren't being opened, leaving you wondering if they're still somehow ending up in the spam folder or, perhaps, a less visible tab.

This scenario suggests a complex interplay between consent, list health, and user engagement. While the emails technically reach an inbox, their lack of engagement indicates they might not be reaching the right inbox, or that recipients simply aren't interested. This article will guide you through navigating these challenges, ensuring compliance, boosting engagement, and accurately diagnosing your email performance.

The foundation of healthy email marketing is explicit consent. Sending emails to individuals who haven't clearly opted in can lead to significant issues, including high spam complaint rates, damage to your sender reputation, and even legal penalties depending on jurisdiction. If you have an unknown number of subscribers who may have been added without proper consent, it's crucial to address this proactively.

The risk of unconsented users

Sending to a non-permission-based list can result in high unsubscribe rates and significant spam complaints. Internet Service Providers (ISPs) like Google and Yahoo are increasingly strict about requiring explicit consent and high engagement. This directly impacts your sender reputation, pushing emails to spam or even blocking them entirely.

When you can't identify who explicitly opted in, you have a few difficult choices. The most cautious approach is to consider all these users as unconsented and remove them. However, this could drastically shrink your list. A more balanced, though still risky, approach is a re-permission campaign. This involves sending an email asking subscribers to re-confirm their interest in receiving your marketing communications. While it might lead to a smaller, but more engaged, list, it carries the risk of losing a large portion of your audience.

Aggressive list pruning

This involves immediately removing any subscriber whose consent status is unclear or unverified.

Pros: Drastically reduces deliverability risk, improves sender reputation quickly, and helps avoid spam traps.
Cons: Significant reduction in list size, potentially removing legitimate, engaged subscribers.

Re-permission campaign

Send a clear, concise email asking users to confirm their subscription.

Pros: Retains some subscribers, builds a highly engaged and compliant list, and signals positive intent to ISPs.
Cons: Expect a drop-off in subscriber count, and the campaign itself might face deliverability challenges if initial reputation is poor.

For new sign-ups going forward, always implement double opt-in. This best practice ensures explicit consent by requiring subscribers to confirm their subscription via an email link. It might slightly reduce list growth speed, but it significantly improves list quality, engagement, and long-term deliverability by reducing spam complaints and bounces.

Decoding high inboxing, low open rates

It's common to see a disconnect between what an Email Service Provider (ESP) reports as an inboxing rate and your actual open rates. If your ESP (using panel data) shows 98% inboxing, but your open rates are around 1-5%, it suggests that while emails are *reaching* a mailbox, they might not be landing in the primary inbox or are being heavily filtered to secondary tabs like Gmail's Promotions tab. Customer feedback indicating emails go to spam further complicates this, as it contradicts the high inboxing rate.

The key here is understanding the difference between delivery and inbox placement. High delivery means the email server accepted the message. High inboxing (especially from panel data) often means it reached *an* inbox, but doesn't always guarantee it landed in the user's primary, visible inbox where they are most likely to open it. Low open rates, despite high delivery, are a clear indicator of low engagement or being filtered away from visibility.

Metric	What it indicates	Implication for low open rates
ESP inboxing rate (Panel Data)	The percentage of emails that successfully reached a recipient's mailbox, as measured by a representative sample of mailboxes.	High means emails are not being hard bounced or blocked at the server level, but doesn't confirm primary inbox placement.
Open rate (Filtered)	Open rates after filtering out automated opens or pre-fetching by security scanners.	A low filtered open rate indicates actual human engagement is poor, pointing to content, subject line, or sender reputation issues.
Open rate (Non-filtered)	Total open rate including all detected opens, even automated ones.	A low non-filtered rate, especially compared to inboxing, means even with potential bot activity, human opens are minimal. This could point to emails landing in secondary tabs.

Investigating the discrepancy

While panel data offers insights, it's crucial to confirm deliverability with your own email deliverability tests using seed lists. These tests send emails to accounts across various ISPs (like Gmail, Outlook, Yahoo) and report actual inbox placement, including which tab the email lands in. This helps verify if your emails are truly hitting the spam folder, or simply the promotions tab, which often explains low open rates with high inboxing. Also check Google Postmaster Tools for detailed spam rates and domain reputation.

Strategies for engagement and list health

Once you've diagnosed the root cause, whether it's poor consent, filtering to secondary tabs, or general disengagement, improving your email program requires a multi-faceted approach centered on list hygiene and engagement. Regularly cleaning your email list is paramount, as inactive or unengaged subscribers can harm your sender reputation over time, even if they aren't marking your emails as spam.

List segmentation: Divide your audience into segments based on engagement, demographics, or purchase history. Send targeted content that resonates with each group.
Re-engagement campaigns: For subscribers who haven't opened in 3-6 months, send a series of emails designed to re-ignite their interest. If they still don't engage, consider suppressing them from future marketing sends. This is crucial for improving deliverability and open rates.
Content optimization: Ensure your email content is valuable, relevant, and engaging. A compelling subject line and preheader text are vital for encouraging opens. Avoid spam trigger words.
Sender name and email address: Use a recognizable and trustworthy sender name. Consider a dedicated marketing sending domain if your transactional and marketing volumes are high.

Beyond engagement, solid email authentication practices are non-negotiable for deliverability. While they might not directly solve low open rates due to tab placement, proper configuration of SPF, DKIM, and DMARC builds trust with ISPs and ensures your emails are perceived as legitimate. This lays the groundwork for better overall inbox placement and reputation.

Example DMARC record for a p=none policyDNS

_dmarc.yourdomain.com IN TXT "v=DMARC1; p=none; rua=mailto:reports@yourdomain.com; ruf=mailto:forensics@yourdomain.com; fo=1; aspf=r; adkim=r;"

Consistently monitoring your deliverability metrics, including open rates, click-through rates, and spam complaint rates, is vital. Use tools like Google Postmaster Tools to track your domain reputation and see if you're hitting spam folders. Regular list cleaning, consistent re-engagement efforts, and compelling content are your best defenses against low open rates, even with strong inboxing.

Views from the trenches

Best practices

Always prioritize explicit consent for new subscribers; double opt-in is a robust standard for maintaining list quality and compliance.

Segment your email list based on engagement levels to tailor content and re-engagement strategies for different audience groups.

Regularly monitor key email metrics, including both filtered and non-filtered open rates, alongside spam complaint rates and deliverability.

Implement a clear re-permission strategy for any legacy subscribers with unclear consent to rebuild a clean and engaged list.

Common pitfalls

Assuming high ESP-reported inboxing rates mean primary inbox placement, ignoring potential filtering to secondary tabs or spam folders.

Failing to implement a formal re-permission process for unconsented users, which risks long-term sender reputation damage and legal issues.

Culling an entire email list based solely on low open rates without deeper diagnosis can lead to losing genuinely engaged subscribers.

Neglecting to monitor spam complaint rates on platforms like Google Postmaster Tools, which can indicate underlying deliverability problems.

Expert tips

If customer feedback suggests emails are going to spam despite good panel inboxing, investigate which domains (consumer or business) are reporting this.

For low open rates with high deliverability, focus on improving subject lines, sender names, and content relevance to drive engagement.

Understand that reputation repair, especially with providers like Microsoft, takes significantly longer than with Google.

Before making drastic list changes, conduct thorough diagnostics to pinpoint the exact nature of the problem, whether it's consent, engagement, or filtering.

Marketer view

Marketer from Email Geeks says that if you are essentially spamming people who did not consent and mixing them with those who did, you will likely need to start over or at least run a re-consent campaign.

December 16, 2022 - Email Geeks

Expert view

Expert from Email Geeks says that it is important to first understand the underlying business goal, whether it is to maximize active users or achieve the cleanest campaign possible.

December 16, 2022 - Email Geeks

Refining your email strategy

Addressing unconsented users and diagnosing perplexing open rate issues requires a commitment to ethical practices and data-driven decisions. Prioritize obtaining explicit consent from your subscribers and maintaining a clean, engaged email list. This forms the bedrock of strong email deliverability and positive sender reputation. Remember, even with high inboxing rates, low open rates signal a problem that needs attention, often relating to content relevance or desired inbox placement.

By proactively managing consent, rigorously testing your inbox placement, and continually optimizing your content for engagement, you can transform a challenging situation into an opportunity to build a more effective and compliant email program. A healthy list leads to better engagement, which in turn reinforces your sender reputation, ensuring your marketing messages consistently reach their intended audience.