How do you define an inactive email subscriber?

Inactive subscribers are typically those who haven't opened or clicked your emails within a specific timeframe, often 90, 120, or 180 days. This period can be adjusted based on your typical customer lifecycle and content frequency.

What are the risks of sending emails to inactive subscribers?

Sending to inactive subscribers can lower your overall engagement rates, signal to mailbox providers that your emails are not relevant, and increase the risk of hitting spam traps or receiving spam complaints. This can negatively impact your sender reputation and lead to emails being sent to spam folders.

How should email content and frequency differ for active versus inactive segments?

For active subscribers, focus on regular, highly personalized, and valuable content, potentially with increased frequency. For inactive subscribers, implement targeted re-engagement campaigns with compelling offers or content, sent at a lower frequency, and be prepared to sunset them if they remain unresponsive.

Should I send to active and inactive segments simultaneously or in sequence?

It's best to send to active segments first to build positive engagement signals with mailbox providers. This can help improve deliverability for subsequent sends to your inactive segments, leveraging the good reputation established by your most engaged users.

What are the risks of using a new domain for acquisition on shared IPs?

If a new domain for acquisition shares IPs with your active audience, it's a high risk. Mailbox providers link reputations across domains and IPs. Poor performance on the new domain (e.g., high spam complaints) can hurt your primary domain's deliverability. It's generally not advisable due to the inherent risk to your established sender reputation.

What are effective strategies for balancing engagement between active and inactive email audience segments? - Sender reputation - Email deliverability - Knowledge base

Balancing engagement across different email audience segments, particularly between active and inactive subscribers, is a common challenge for many email marketers. The goal is to maximize the impact of your campaigns without jeopardizing your sender reputation, which can lead to emails landing in the spam folder or even getting your domain (or IP) placed on a blocklist (or blacklist). It's a delicate act, requiring careful strategy and consistent monitoring to ensure both segments contribute positively to your overall email program health.

The key lies in understanding that not all subscribers are created equal. Active users expect certain content and frequency, while inactive users require a different approach, often focused on re-engagement or, in some cases, eventual removal from your list. Treating them all the same is a recipe for diminishing returns and potential deliverability issues.

Segmenting your audience

Audience segmentation is fundamental to effective email marketing. Dividing your email list into smaller, more manageable groups allows you to tailor your messaging, frequency, and overall strategy to each segment's specific behaviors and interests. For active subscribers, this might mean more frequent, personalized content, while inactive subscribers may receive targeted re-engagement campaigns.

A crucial aspect of segmentation is defining what constitutes an 'inactive' subscriber. This definition can vary, but generally, it refers to subscribers who haven't opened or clicked an email in a specific period, such as 90, 120, or even 180 days. Regularly identifying these individuals is the first step towards managing them effectively without negatively impacting your overall domain reputation.

Sending to a large number of inactive subscribers can dilute your engagement rates, which mailbox providers (like

Google and

Yahoo) closely monitor. Low engagement signals to them that your emails are not relevant, potentially leading to increased spam classifications and a damaged sender score. This is why a strategic approach to inactive segments is not just good practice, but essential for deliverability.

Identifying inactive subscribers

Engagement metrics: Track opens, clicks, and conversions. Define inactivity based on a lack of these actions over a specified period, e.g., 90-180 days.
Segmentation rules: Implement automated rules in your email service provider to move subscribers into an inactive segment once they meet your criteria.
Historical data: Analyze past engagement trends to refine your inactivity definition and identify potential re-engagement opportunities.

Strategies for active segments

For your active subscribers, the strategy is about nurturing and maximizing their engagement. These are your most valuable recipients, and their consistent interaction helps bolster your sender reputation. Focus on delivering highly relevant, valuable, and timely content. This might involve increasing email frequency for engaged subscribers, provided the content remains valuable and doesn't lead to fatigue.

Personalization plays a huge role here. Leveraging data about their past purchases, browsing behavior, or expressed interests can help you craft emails that truly resonate. This not only keeps them engaged but also reinforces the positive sender-recipient relationship that mailbox providers favor. Strong engagement from this segment can help offset any negative impacts from your less active lists.

When considering sending to both active and inactive segments, it's generally advisable to send to your active segments first. This establishes a positive sending reputation with mailbox providers, showing them that your emails are generally well-received. This positive signal can then help improve the deliverability of subsequent sends to less active (or inactive) segments, effectively leveraging the good behavior of one group to benefit the other.

Active segment approach

High frequency: Send emails more frequently, aligning with their demonstrated interest and engagement levels.
Personalization: Tailor content based on behavior, preferences, and past interactions to maximize relevance.
Value-driven content: Offer exclusive content, early access, or loyalty rewards to reinforce their active status.

Inactive segment approach

Low frequency: Reduce email frequency to avoid further disengagement and potential spam complaints.
Re-engagement campaigns: Implement specific campaigns to win back their attention with compelling offers or content.
Clear call to action: Provide an easy way to update preferences or opt-out, maintaining list hygiene.

Re-engaging inactive subscribers safely

Re-engagement campaigns are specifically designed to coax inactive subscribers back into active participation. These campaigns should be carefully crafted, often with a different tone and purpose than your regular marketing emails. The goal is not just to get an open, but to encourage a meaningful interaction that signals renewed interest. You can learn more about email re-engagement campaigns.

When sending to inactive users, it's wise to limit the volume. A common guideline is to maintain a ratio of approximately 80% active to 20% inactive (or even 70% active to 30% inactive) in any given send, if you're mixing them. This helps ensure that the positive engagement from your active users outweighs any potential negative signals from the inactive ones. If your inactive list is very large, consider breaking it into smaller chunks and sending over a longer period, allowing more time for individual responses and reducing the immediate risk to your sender reputation.

If a subscriber remains unresponsive after a re-engagement series, it may be time to consider sunsetting them from your list. While it might seem counterintuitive to remove subscribers, it's a critical step for maintaining a healthy and engaged list. Removing unresponsive addresses reduces your bounce rate, lowers the risk of hitting spam traps, and ultimately improves your overall deliverability, ensuring your emails reach those who want to receive them.

Example subject lines for re-engagement campaigns

Subject: We miss you! Here's 20% off.
Subject: Still interested? Update your preferences.
Subject: Last chance to stay subscribed! ✨

Maintaining a clean email list through regular list hygiene practices is paramount. A high number of unengaged recipients can significantly impact your domain's reputation. Mailbox providers interpret low engagement (low opens, clicks) and high negative feedback (spam complaints) as signs of unwanted mail. This can lead to your emails being filtered to spam folders, or worse, your IP or domain being added to a major email blacklist.

Avoiding blacklists and maintaining reputation

When your domain or IP is listed on a blocklist, your emails will likely be rejected or routed to the spam folder by receiving mail servers. This is why continuously monitoring your sender reputation and checking for blacklists is essential. Early detection allows you to take corrective action, such as adjusting your sending practices or requesting removal from the blocklist, before significant damage occurs.

One common pitfall is trying to use a separate domain for acquisition or cold outreach, particularly if it shares the same IP address as your active audience sends. Mailbox providers are sophisticated, and they

track reputation across various identifiers, including domains, IPs, and combinations thereof. If the new domain generates high spam complaints, it can easily impact the reputation of your established domain sharing the same IP, leading to deliverability issues for your legitimate marketing emails.

The risks of poor sender reputation

Reduced inbox placement: Emails are more likely to land in spam folders or be rejected outright.
Blacklisting (or blocklisting): Your IP or domain might be added to a public or private blacklist, severely impacting deliverability.
Damage to brand trust: Consistent spam filtering can erode subscriber trust and brand perception.

Key takeaways

Balancing engagement between active and inactive email segments is a continuous process that requires a data-driven approach. By strategically segmenting your audience, tailoring your content and frequency, and implementing careful re-engagement strategies, you can maintain a healthy sender reputation and ensure your emails reach the right inboxes. Remember, the health of your email list directly impacts your deliverability and the success of your entire email program.

Views from the trenches

Best practices

Always segment your audience by engagement level, sending to active users first to establish a positive reputation before targeting less active ones.

Use clear, compelling calls to action in re-engagement campaigns and make it easy for subscribers to update their preferences or unsubscribe.

Implement automated processes to identify and move inactive subscribers into a dedicated segment, preventing them from harming your primary sending reputation.

Maintain a consistent and valuable content strategy for active subscribers to maximize their engagement and ensure high deliverability.

Common pitfalls

Sending the same content and at the same frequency to both active and inactive segments, leading to decreased engagement and increased spam complaints.

Ignoring inactive subscribers, allowing them to accumulate and dilute overall engagement metrics, which can negatively impact sender reputation.

Using a new domain for cold outreach or spamming on the same IP as your active audience, which can quickly blacklist both domains.

Failing to track and act on key engagement metrics, leading to an uninformed strategy for managing different audience segments.

Expert tips

Consider sending one more email to your active segment than your inactive segment over a given period to ensure consistent high engagement signals.

Further segment inactive users by the number of days since their last interaction, allowing for more granular re-engagement strategies.

Prioritize sending to active users first to 'warm up' your sending reputation for the day, which can then positively influence subsequent sends to inactive lists.

Always question the source of consent for new acquisition lists, as sending to non-consented users is a high risk for your domain reputation.

Expert view

Expert from Email Geeks says the inactive segment can definitely drag down your active segments' performance, and mailbox providers attach reputation to every identifiable aspect of your email, including domain, IP, and link domains.

2023-01-16 - Email Geeks

Expert view

Expert from Email Geeks says sending to inactives is sometimes necessary, but it needs a clear strategy for handling those who remain unresponsive, including data deletion in some regions. A ratio of 80% active to 20% inactive, or even 70/30, can be acceptable.

2023-01-16 - Email Geeks