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The Importance of List Hygiene

Kelly Sutter

Email marketing and subscriber lists go hand-in-hand. The importance of list hygiene cannot be minimized. You might have exceptional looking emails, but if your list contains spam traps and inactive addresses, they might not be reaching the inboxes of your best subscribers.


What is list hygiene?

In general, hygiene refers to the habits we learn to maintain good health. Cleanliness is at the core of good hygiene practices. Many diseases can be transmitted within communities when surface areas or foods we consume are not properly sanitized.

List hygiene is essentially the practice of keeping clean subscriber lists. Poor list hygiene leads to blocklists and low inbox deliverability. Good list hygiene leads to the best deliverability and high engagement stats.


3-step plan for proper list hygiene

Step 1. Acquire the right addresses

Collecting real opted-in subscriber addresses is the first step in list hygiene. This is critical. Beware of quick list growth methods like purchased lists. There is no such thing as a targeted or opted-in purchased list. Subscribers should be given the opportunity to opt-in to your email program.

Take a deeper dive by reviewing our post: The Right Way to Subscribe.

Step 2. Suppress opt-outs and hard bounces

After you’ve done the hard work of acquiring subscribers the right way, the next step is managing subscriber’s sending status. Subscribers who opt-out or submit abuse complaints should be removed from your list immediately – this is the law in both the US and internationally. Addresses that hard bounce are always invalid and all ISP postmaster guidelines ask senders to remove these addresses immediately. Resist the urge to resend to hard bounce addresses for any reason. Consider the opt-out and hard bounce as the end of the relationship with the subscriber.

Learn more about managing opt-outs: The Right Way to Unsubscribe.

Step 3. Remove inactive subscribers

Over time even a good address can change to a bad one. Subscribers change mailbox providers and their inbox becomes dormant. ISPs convert inactive mailboxes to their own spam traps, or the addresses become part of mainstream blocklists like Spamhaus. Mailing to spam traps is the primary reason senders end up on blocklists. Sending to opted-in and actively engaged subscribers is the only way to avoid spam traps. Subscribers with no activity (opens and clicks) for 6 months should be removed from your lists.

We know, saying goodbye can be so hard! Try running a re-engagement campaign to see if any subscribers still want to receive emails. Subscribers that don’t respond to re-engagement emails should be removed from your mailing lists.

Learn more about list management: Re-Engage for Better Results and Suppressing inactive subscribers


Key takeaways

List hygiene is at the core of every successful email program. It takes hard work to grow lists organically, but the costs of ignoring best practices are real. Sending to purchased lists, spam traps, and bad addresses will land your email program on one of many blocklists. Why decrease the chance of your message reaching the recipient? Keep list hygiene front of mind and practice to successfully reach your subscribers.