Preserving Deliverability and Saving You Money with Automated List Purging

Delivering opportunity is what we do. Our goal is to help you to find your people, to engage with them and their passions.

We encourage all publishers to follow best practices in acquiring new subscribers and regularly use list hygiene to remove inactive subscribers. To accomplish this, we monitor the quality of every list to ensure that these standards are met. As well as keeping a list's open rate high, performing list hygiene (i.e. removing unengaged list members) ensures you do not pay for subscribers who are not interacting with your emails.

Over time, without list hygiene, it is normal for a list's open rate to decline, especially if new subscriber acquisition is not keeping the list healthy and growing. 

Internet Service Providers (ISPs) notice when an email address is regularly mailed by an Email Service Provider (ESP - that's us, FeedBlitz), and the account has either gone dormant or the account does not interact with the emails. This lack of interaction can result in your emails being deprioritized (showing up lower in algorithmic-based inboxes) by the ISP, landing in the spam folder, or worse, damage to your sender reputation.

To manage these risks to you - and, as a side benefit, potentially save on our fees - FeedBlitz sets minimum required open rates, and automatically removes non-engaged list members in order to drive your open rates up if these minima are not met. These policies are applied to larger, active lists, and may also affect other list settings (see below). This policy exists as a mechanism to reduce the risk of a list suspension for violating our strict quality policies. 

That said, most FeedBlitz lists will never experience this automated subscriber purge process, as the average open rate for lists we power is 33% per mailing (Jan-May, 2022).

Automated List Purge

If your list needs it, applying this policy has several benefits. It reduces the risk that your list will be suspended for quality reasons; it can save you the hassle of initiating a list hygiene program yourself; and it can save you money. 

The automated list purge protocol only goes into effect when a list meets all of the following criteria:

  • The list has over 10,000 subscribers (May 2022).
  • The list has been mailed four or more times in the last 30 days.
  • The list's average open rate is less than five percent (May 2022), rising monthly to 10% in October 2022 and thereafter.

NB: The minimum list size will fall monthly (to 5,000) by October 2022. 

The automated purging protocol uses an algorithm to determine who to remove from the list. This algorithm has two main variables, time and interaction. Time is first determined by the age of the list within FeedBlitz.

If the list is:

  • One year or greater, the window is 180 days.
  • 180 - 365 days, 90 days
  • 90 - 180, 45 days
  • less than 90 days, 30 days

Please note that if the list has been mailed 20 or more times in the last 30 days, the interaction window is reduced to 30 days or less in some cases.

The second variable used by the algorithm is interaction. A list member will be removed if they have not interacted with any of the mailings sent in the applicable time frame. If you have more than one list in FeedBlitz, however, the algorithm will allow the subscriber to remain on the list being processed if they have interacted with any of your lists within the window.

What happens to removed subscribers? 

Subscribers removed from a list by the algorithm are set to a special archived status, and they won't be emailed going forward. They do not count toward your total subscribers for billing purposes.

What happens to the list?

Lists that don't meet our minimum engagement criteria and also have subscribers removed by this process will also have their single opt-in status revoked, if that privilege has been granted. Otherwise, no other list settings are affected.


If an open or click is later detected in an email that belongs to a subscriber that has been archived by this process, the subscriber will immediately be restored to active status in your list.

If you have any questions, please don't hesitate to let us know. You can find all of our great support resources and how to get in touch with us via email, chat or phone on our Support Page.

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