How do unengaged subscribers affect email deliverability?

Sending to unengaged subscribers can harm your deliverability by lowering open rates, increasing spam complaints, and boosting bounce rates. Mailbox providers interpret these low engagement signals as a sign of irrelevant content or poor list hygiene, which can lead to reduced inbox placement and even blacklisting (blocklisting).

What is the best way to re-engage inactive email subscribers?

The key is to segment them based on their last engagement (e.g., no opens or clicks in 90, 180, or 365 days). Then, send them specific re-engagement campaigns with tailored content, such as a "We Miss You" message, an offer to update preferences, or a special discount. If they still don't engage after a few attempts, implement a sunset policy to remove them from your active list.

What is a sunset policy in email marketing, and why is it important?

A sunset policy defines when to stop sending emails to continuously unengaged subscribers. The timeframe varies by industry and sending frequency, but common ranges are 6 to 12 months of inactivity. This practice is crucial for maintaining a healthy sender reputation and improving overall email deliverability by ensuring you only send to genuinely interested contacts.

Should the content for unengaged campaigns be the same as for active recipients?

No, you should not send the same type of campaign to both active and unengaged users. Active users typically receive your regular promotional or informational content. Unengaged users require specific re-engagement messages designed to elicit a response or confirm their interest, often with a different tone or offer. Mixing them can lead to poor performance for the entire send.

Should unengaged email subscribers be sent separate campaigns or mixed with active recipients? - Sender reputation - Email deliverability - Knowledge base

Q: Should unengaged email subscribers be sent separate campaigns or mixed with active recipients?

It is generally recommended to send unengaged subscribers separate campaigns. Mixing them with active recipients can negatively impact your overall engagement metrics and sender reputation, potentially causing your emails to land in spam folders for all recipients. Segmenting allows for targeted re-engagement strategies without risking your main email stream.

Managing unengaged email subscribers is a persistent challenge for marketers. The core question often boils down to whether to send these dormant contacts separate campaigns or to simply mix them in with your active, highly engaged recipients. This decision has significant implications for your email deliverability and overall sender reputation.

The common intuition might suggest that diluting the poison, as some refer to it, by mixing unengaged users with active ones could mitigate the negative impact. The idea is that the strong engagement metrics from your active list might offset the poor performance from the unengaged segment, making the overall campaign look healthier to mailbox providers. However, this approach often carries more risk than benefit.

Mailbox providers, like

Google and

Yahoo, continuously assess sender reputation based on engagement signals. Low open rates, high complaint rates, and increased bounces from sending to unengaged contacts can severely damage your sender reputation, regardless of the active portion of your list. This can lead to your emails being flagged as spam, even for your most engaged subscribers.

Why unengaged subscribers hurt deliverability

Sending emails to unengaged contacts can significantly hurt your overall deliverability. When a large percentage of your recipients consistently ignore, delete, or mark your emails as spam, it signals to internet service providers (ISPs) that your content is not relevant or desired. This negative feedback loop can lead to your domain or IP address being placed on a blacklist or blocklist, making it harder for all your emails, even those to active users, to reach the inbox.

ISPs (Internet Service Providers) and mailbox providers utilize sophisticated algorithms to evaluate sending behavior. If a campaign includes a substantial number of unengaged recipients, the low open rates and other negative metrics for that specific campaign (or even the overall sending IP/domain) can drag down your sender score. This means that even if you have a perfectly crafted email for your active audience, its chances of landing in the inbox are diminished if it's sent alongside or immediately after a low-engagement batch.

Maintaining a clean and engaged email list is paramount for good deliverability. Sending to unengaged subscribers wastes resources, inflates your list size with contacts who aren't converting, and most importantly, puts your sender reputation at risk. It is a critical factor in why your emails might be going to spam.

The risk of mixing lists

Including unengaged subscribers in your regular campaigns can dilute your overall engagement metrics. A lower overall open rate, for instance, can negatively impact how ISPs perceive your sending domain for future campaigns, even for your most active subscribers.

Increased spam complaints

Unengaged subscribers are more likely to mark your emails as spam, even if they once opted in. These spam complaints significantly harm your sender reputation and can lead to immediate blocklisting (blacklisting) by mailbox providers.

Higher bounce rates

Sending to old or unverified email addresses increases hard bounce rates, which also negatively affects your sender score. Regular list cleaning and segmentation can reduce this risk.

The benefits of separate campaigns

The consensus among deliverability experts is to segment your unengaged subscribers and send them separate, highly targeted campaigns. This strategy offers several benefits that protect your main sending reputation and allow for more effective re-engagement attempts.

By isolating unengaged contacts, you ensure that their low engagement metrics do not negatively impact the performance of your regular campaigns. This approach allows your active subscriber list to maintain high engagement rates, which in turn reinforces a positive sender reputation with ISPs. High engagement for your main sends helps ensure they continue to land in the inbox.

Separate campaigns also provide an opportunity to tailor your messaging specifically for re-engagement. A generic marketing email sent to an unengaged subscriber is unlikely to spark interest. Instead, a dedicated re-engagement strategy can focus on value propositions, updated preferences, or simply asking if they still wish to receive your emails. This highly personalized approach increases the chances of rekindling their interest or, alternatively, prompting them to unsubscribe gracefully, which is also a positive outcome for list hygiene.

Mixing unengaged with active recipients

Impact on metrics: Your overall open and click-through rates will decline, masking the performance of your engaged audience.
Sender reputation: Risk of lower inbox placement for all emails, as low engagement signals negative reputation to ISPs.
Content relevance: Cannot tailor messaging for different engagement levels effectively.

Sending separate campaigns to unengaged recipients

Impact on metrics: Maintains high engagement rates for active segments, improving overall deliverability.
Sender reputation: Protects your primary sender reputation from negative signals of unengaged users.
Content relevance: Allows for highly personalized re-engagement messages.

Re-engagement campaign strategies

When approaching unengaged subscribers, a dedicated strategy is crucial. The goal isn't just to get an open, but to either rekindle genuine interest or respectfully remove them from your list. Start by defining what "unengaged" means for your specific audience, whether it's no opens or clicks in 90 days, 6 months, or even a year, depending on your typical email frequency.

Your re-engagement campaigns should be distinctly different from your regular marketing sends. Consider offering special incentives, asking for updated preferences, or using a "We Miss You" subject line. The content should be short, to the point, and clearly state its purpose, which is to re-establish a connection or understand if they still want to hear from you.

It's also beneficial to send these re-engagement emails from a slightly different sending profile or even a separate subdomain if possible. This way, any negative impact, such as increased spam complaints or low engagement, is contained and does not affect the reputation of your primary sending domain, which is used for your active subscribers. This is part of a broader strategy for targeting inactive email users safely.

When to consider a separate IP

For very large lists or if historical data shows significant negative impact from unengaged segments, consider using a dedicated IP address (or a shared IP with a very low-reputation pool) for re-engagement campaigns. This acts as a "time-out" IP, protecting your main IP from potential damage. It's a strategic move for larger senders to splitting email sends.

Implementing a sunset policy

Even with the best re-engagement efforts, some subscribers will remain unengaged. At this point, it's crucial to implement a sunset policy. A sunset policy dictates when to stop sending to persistently inactive subscribers and remove them from your list. This is a vital part of email list hygiene.

The timeframe for sunsetting can vary depending on your industry and email frequency. For some, 6 months of no engagement is sufficient, while for others, it might be a year. The key is to define this threshold clearly and consistently apply it. Continuing to send to these addresses not only harms your deliverability but also wastes marketing resources.

Remember, a smaller, more engaged list is always more valuable than a large list filled with inactive contacts. Removing unengaged subscribers (or placing them on a deep suppression list) contributes to a healthier sender reputation and better overall campaign performance. It's a strategic decision that prioritizes long-term deliverability over inflated list numbers.

Example sunset policy definition (90 days)

Example LogicSQL

IF last_open > 90 days AND last_click > 90 days THEN mark_as_unengaged
IF unengaged_status_age > 30 days AND re_engagement_campaign_sent = TRUE AND no_engagement THEN remove_from_active_list_or_suppress

This pseudo-code demonstrates a basic logic for identifying and managing unengaged subscribers over a 90-day period. Adjust timeframes based on your specific sending patterns and audience behavior. Always provide a clear opt-out path in re-engagement emails. You can also refer to guides on when to remove unengaged subscribers.

Views from the trenches

Best practices

Always segment your unengaged subscribers into a separate list for dedicated re-engagement efforts, protecting your primary sending reputation.

Tailor re-engagement campaign content to address inactivity directly, offering value or preference updates.

Use a different sending subdomain or IP for re-engagement campaigns to isolate any negative impacts.

Implement a strict sunset policy to remove or suppress subscribers who do not re-engage after multiple attempts, maintaining a clean list.

Common pitfalls

Mixing unengaged subscribers with active recipients in regular campaigns, which can artificially deflate overall engagement metrics.

Ignoring unengaged subscribers, allowing them to accumulate and eventually harm your sender reputation through spam complaints or blocklists.

Sending the same generic marketing content to unengaged subscribers, which is unlikely to prompt a re-engagement.

Failing to track engagement metrics separately for re-engagement campaigns, making it difficult to assess effectiveness.

Expert tips

Monitor your engagement rates closely after segmenting. You should see an immediate improvement in open and click rates for your active segments.

Consider a phased approach for re-engagement, starting with gentle reminders before more direct inquiries or offers.

For very large unengaged lists, 'warm up' a new, less critical IP address specifically for re-engagement efforts to absorb any potential reputation hits.

Educate stakeholders on the long-term benefits of list hygiene and segmentation versus the short-term perceived gain of a larger mailing list.

Expert view

Expert from Email Geeks says that sending a special message to inactive subscribers makes more sense than sending them the standard message.

2019-06-20 - Email Geeks

Expert view

Expert from Email Geeks says that you can leverage the existing domain and IP reputation for separate inactive sends, provided it is done reasonably.

2019-06-20 - Email Geeks

Protecting your email program

The question of whether to send unengaged email subscribers separate campaigns or mix them with active recipients has a clear answer: separation is almost always the superior strategy. It safeguards your sender reputation, allows for tailored re-engagement efforts, and ultimately leads to a healthier, more profitable email program.

By understanding the impact of unengaged subscribers on your deliverability and implementing thoughtful segmentation and re-engagement strategies, you can prevent damage to your sender score and ensure your valuable emails consistently reach your active audience. Regularly reviewing and refining your approach to inactive subscribers is a continuous process that pays dividends in long-term email marketing success.