Email list hygiene: what Klaviyo cleans for you, and what it leaves to you
Most of the cleaning happens on its own. The part that doesn't is the part that hurts, and it always needs somebody to make a decision.
- 075List Hygiene
- Regularly cleaning your email list by removing invalid or unengaged subscribers to improve deliverability.
- Automatic in Klaviyo
- Hard bounces, repeated soft bounces and spam complaints
- Left to you
- Silent subscribers, unproven consent and fake sign-ups
- Done by
- Suppressing, not deleting
- Runs as
- Standing rules, not a yearly purge
What Klaviyo cleans up without being asked
Good news first. Klaviyo suppresses an address when it hard bounces, suppresses one that soft bounces over and over, and unsubscribes anyone who marks you as spam. Suppressed profiles are skipped on every send, so you can't mail them by mistake.
| Problem | Klaviyo handles it | Your job |
|---|---|---|
| Hard bounces | Yes, suppressed | Ask where a sudden batch came from |
| Repeated soft bounces | Yes, after a long run | Usually nothing |
| Spam complaints | Yes, unsubscribed | Work out what they objected to |
| Subscribers gone silent | No | A sunset rule |
| Addresses with no consent record | No | Suppress what you can't prove |
| Typos and fake sign-ups | No | Catch them at the form |
The addresses that hurt you never bounce
Here's the hard truth: a dead address is the easy kind. It bounces, Klaviyo suppresses it, done. The damage comes from addresses that accept your mail and never react.
- Spam traps, including long-abandoned addresses a mailbox provider has turned into a test of who cleans their list
- Mistyped addresses on domains set up to catch exactly that
- Bots filling your form with real people's addresses
- Competition entrants who wanted the prize, not the emails
None of them complain. They just sit there, telling the mailbox providers you don't check who you're mailing. The defence is to stop sending to people who never engage, and never to buy a list, which Google's sender guidelines rule out in plain words.
Suppress, don't delete, and let the rules run
Suppressing keeps the record and stops the sending. Delete a profile instead and the next import can bring the address straight back, history gone. Deleting is for an erasure request under UK GDPR, not for tidying up.
- An engaged segment as the default audience for every campaign
- A sunset flow that suppresses the long-silent after one last email
- Double opt-in on any form that attracts junk sign-ups
- A look at bounces after every import and every unusually big send
- No bought or rented lists, ever
Rules beat purges. A purge happens the week after a scare. A rule runs every day, whether anyone remembers it or not.
Related terms
FAQs
How often should we clean our email list?
Every day by rules, and properly once a quarter by a person. The rules are your sunset flow and an engaged default audience. The quarterly look checks they're still working: what got suppressed, what arrived, and whether the engaged segment is growing. Big imports get checked the day they land.
Is an email verification tool worth paying for?
At the door, yes. Checking addresses as people sign up, or before you import an old file, catches typos, dead domains and obvious fakes. What it can't tell you is whether someone wants your email, and it won't catch every trap. Your engagement rules do that part.
Can we buy an email list to grow faster?
No. Google's sender guidelines tell you not to buy addresses, and consent given to another company doesn't carry over to yours under UK rules. You'd be mailing strangers through a reputation you spent years building. It's the quickest way there is to undo it.
Rather we explained it on your own account?
Bring your Klaviyo account to a growth consultation. We'll walk through what this means for your numbers, in plain English, and what we'd fix first.
Half an hour with Theo, our founder.
We're all about relationships built on trust, mutual respect and a shared vision for success. If that sounds like your vibe, let's make some waves together 🌊
