Summary
Maintaining good email list hygiene is critical for deliverability and sender reputation. The consensus is that you should regularly scrub your list, but the exact timeframe varies. A common strategy involves a re-engagement campaign after 3-6 months of inactivity, with a possible hard cutoff for removal at 24 months. Factors influencing this timeline include email type (newsletter vs. marketing), mailing frequency, industry, engagement metrics (opens/clicks), and whether the email address is free or paid. Ignoring inactive users can lead to deliverability issues, hitting spam traps, and being flagged as spam by providers like Google and Microsoft. Quality over quantity is paramount.
Key findings
- Re-engagement First: Implement a re-engagement campaign after 3-6 months of inactivity.
- Purge After Re-engagement: Remove unengaged subscribers after a failed re-engagement campaign.
- Quality Over Quantity: Prioritize list quality over list size; a smaller, engaged list is better than a large, unengaged one.
- Google Penalizes: Sending to abandoned addresses on Google can negatively impact deliverability.
- Microsoft and Yahoo Bounce: Yahoo and Microsoft often bounce inactive emails, reducing the urgency of purging, but not eliminating it.
- Clean Regularly: Regular list cleaning is essential to prevent deliverability issues.
Key considerations
- Email Type: Consider the type of email (newsletter vs. marketing) when determining inactivity periods.
- Mailing Frequency: Adjust the purging timeframe based on how frequently emails are sent (shorter for frequent senders).
- Engagement Metrics: Monitor engagement metrics (opens, clicks, conversions) to identify inactive subscribers.
- Address Type: Consider the type of email address (free vs. paid) - paid addresses might remain active longer.
- Industry Standards: Take into account industry-specific best practices and norms.
- Delivery Issues: Assess any delivery issues that might indicate broader problems with your list.
- Spam Traps: Purging helps avoid recycled spam traps.
What email marketers say
10 marketer opinions
The optimal time to remove inactive email addresses from a marketing list depends on various factors, but a common practice is to implement a re-engagement campaign after a period of inactivity (ranging from 3-6 months, or 6-12 months). If subscribers remain unengaged after the re-engagement campaign, purging them from the active list is generally recommended to maintain good sender reputation and improve deliverability. The frequency of emails sent and the type of email (newsletter vs marketing) can influence the ideal timeframe for removing inactive subscribers.
Key opinions
- Re-engagement: Implement a re-engagement campaign after 3-6 months or 6-12 months of inactivity.
- Purging: Purge unengaged subscribers after a failed re-engagement campaign.
- Frequency: Adjust removal timeframe based on email frequency; shorter for frequent emails, longer for infrequent emails.
- Deliverability: Removing inactive subscribers enhances deliverability and sender reputation.
- List Quality: List quality is more important than list size.
Key considerations
- Engagement Metrics: Regularly assess engagement metrics like opens and clicks to determine inactivity.
- Graymail Segmentation: Consider segmenting inactive subscribers into a graymail list with reduced email frequency before complete removal.
- Industry Standards: Determine any industry-specific best practices or benchmarks for list cleaning.
- Email Type: Consider type of email eg. newsletter or marketing.
Marketer view
Email marketer from Litmus explains that the size of the list is not as important as the quality of the list. It recommends removing subscribers who haven't engaged in 6-12 months.
8 Nov 2024 - Litmus
Marketer view
Email marketer from SuperOffice states that after 6 months of inactivity, you should run a re-engagement campaign.
16 Nov 2022 - SuperOffice
What the experts say
4 expert opinions
Experts recommend regularly scrubbing email lists to remove inactive addresses to maintain deliverability and avoid spam traps. The timeframe for purging inactive emails varies, ranging from 90 days to 2 years, and depends on factors such as the type of email (newsletter vs. marketing), email address type (free vs. paid), mailing frequency, industry, and potential delivery issues. It's crucial to consider that sending to abandoned addresses, especially on Google, negatively impacts deliverability, while Yahoo and Microsoft bounce inactive emails.
Key opinions
- Purging Prevents Issues: Purging inactive addresses avoids hitting spam traps and improves deliverability.
- Timeframe Varies: The timeframe for purging ranges from 90 days to 2 years, dependent on several factors.
- Older Lists Problematic: Older email lists have more deliverability problems.
- Google's Impact: Sending to abandoned addresses on Google hurts deliverability.
Key considerations
- Email Type: Differentiate between newsletters and marketing emails when determining inactivity period.
- Address Type: Consider whether email addresses are free or paid (e.g., broadband addresses are typically valid longer).
- Mailing Frequency: Adjust the purging timeframe based on how frequently emails are sent.
- Industry: Consider industry-specific benchmarks and mailing practices.
- Bouncing Behavior: Factor in whether email providers bounce inactive emails (Yahoo and Microsoft do).
- Purchase Cycle: Consider the customer purchase cycle.
Expert view
Expert from Word to the Wise recommends purging inactive email addresses to avoid hitting recycled spam traps. They suggest considering purging addresses that haven't engaged in 12-24 months, depending on the mailing frequency and industry.
20 Jun 2022 - Word to the Wise
Expert view
Expert from Email Geeks shares that a reasonable timeframe for email list expiration is between 90 days and 2 years, depending on the purchase cycle and delivery issues.
9 Nov 2024 - Email Geeks
What the documentation says
4 technical articles
Email deliverability documentation consistently emphasizes the importance of maintaining clean email lists by removing inactive addresses. Sending emails to invalid recipients, especially those that become spam traps, and consistently sending to unengaged users negatively impacts sender reputation, deliverability rates, and could lead to email blocking. Actively managing bounced emails and suppressing inactive users is also recommended.
Key findings
- List Hygiene is Key: Maintaining good list hygiene by removing inactive addresses is crucial for protecting sender reputation.
- Avoid Spam Traps: Sending to invalid email addresses, especially spam traps, severely damages sender reputation.
- Manage Bounces: Actively managing bounced emails and suppressing inactive users is recommended.
- Avoid Inactive Users: Google interprets sending to inactive users as spamming behavior.
- Remove Invalid Recipients: Microsoft may direct emails from senders who send high amounts of email to invalid recipients to spam or block them entirely.
Key considerations
- Complaint Rates: High complaint rates from users opening but not clicking negatively impact deliverability.
- Engagement Rates: Low engagement rates negatively impact the ability of future emails to reach inboxes.
- Be Proactive: Err on the side of caution and remove addresses that haven't engaged in a while.
Technical article
Documentation from Google Postmaster Tools recommends actively managing bounced emails and suppressing inactive users. Google can interpret consistently sending to inactive users as spamming behaviour.
21 Jan 2024 - Google Postmaster Tools
Technical article
Documentation from MessageBird emphasises that sending to invalid email addresses, especially spam traps, can severely damage your sender reputation. It's better to err on the side of caution and remove addresses that haven't engaged in a while.
14 Jan 2024 - MessageBird
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