Email List Hygiene
Email list hygiene keeps audience data and sending permissions current. Handle invalid addresses, opt-outs, complaints, and inactivity according to their different causes.
Email list hygiene is the routine of removing or pausing addresses that can't or don't want to receive your email: invalid addresses, unsubscribes, spam complaints and long-inactive contacts. Keeping them out holds bounce and complaint rates down, which protects your sender reputation and inbox placement.
It is also called email hygiene or list cleaning, and it covers permissions as well as addresses: a stale import should never quietly resubscribe someone who opted out. To review hygiene alongside consent, data, and lifecycle coverage, run the SaaS email program audit.
What to clean
Hard bounces. Stop sending after the first permanent failure, such as a mailbox that doesn't exist. See hard bounce.
Spam complaints. Stop all email to anyone who marks you as spam, and keep them on your suppression list.
Unsubscribes. Honor them promptly and keep the record, so the next import can't add the address back.
Soft bounces. Temporary failures such as a full mailbox. Let your provider retry, and read the SMTP error code before treating the address as dead. See soft bounce.
Inactive contacts. People who haven't used the product or clicked in months. Pause marketing to them before you remove anyone.
Bad signups. Typos, disposable addresses and bots. Stop them at the form with validation, a captcha or double opt-in.
Separate failures from inactivity
An absence of recorded opens does not establish inactivity. Apple Mail Privacy Protection and image blocking distort open tracking, and Google says it does not track open rates at all. Use product activity, replies, and qualified clicks instead, and filter out automated clicks.
A validation service can flag some address problems. It cannot tell you whether the person agreed to receive your marketing.
How often to clean your list
Suppress hard bounces and complaints on every send. Most sending tools do this automatically. Review inactive contacts on a fixed schedule, such as every quarter, and before any large campaign or import.
Worked example
Before its quarterly product update, Acme, a project management app, reviews 18,000 marketing contacts. 240 were already suppressed after hard bounces or complaints, so they won't be emailed. 3,100 haven't logged in for 180 days, based on a lastActive date Acme's app writes to each contact.
Those 3,100 get one email asking whether they still want product updates, with a single button to stay subscribed. Two weeks later, everyone who didn't click is unsubscribed from marketing, and the record stays so an old export can't bring them back. The update goes to everyone else.
List hygiene in Loops
Loops suppresses a contact automatically after a hard bounce or spam complaint, and later sends to that address show as hard bounces. Soft bounces are retried. The email blocklist stops addresses, domains, or whole TLDs from joining your audience through forms, CSV uploads, the API, and integrations, and double opt-in keeps unconfirmed form signups out of marketing sends.
Loops filters can't compute rolling dates like "inactive for 90 days", so write an activity property such as lastActive or isActive30d from your app and filter on it, as in this active users recipe. Loops' docs also advise against third-party list-cleaning services, which can flag valid mailboxes and create probe traffic.
Before the next import
Check where the records came from, what people agreed to receive, and whether the file predates any opt-outs. Keep current unsubscribes and suppressions in place, and treat conflicting records as a reason to investigate rather than assuming the imported value is newer. More on keeping mail out of spam: why emails go to spam.
FAQ
What is email list hygiene?
Email list hygiene is the routine of removing or pausing addresses that can't or don't want to receive your email, such as invalid addresses, unsubscribes, spam complaints, and long-inactive contacts.
How often should you clean your email list?
Suppress hard bounces and complaints on every send. Review inactive contacts on a fixed schedule, such as every quarter, and before any large campaign or import.
Should I delete inactive subscribers?
Pause marketing to them first and send one email asking whether they still want to hear from you. Unsubscribe the ones who don't respond, and keep the record so a later import can't add them back.