Growing an email marketing list is a critical element of a strong email marketing program. But it’s equally important to complement those efforts with regular email list cleaning.

Also known as “scrubbing,” email list cleaning is a process where you remove inactive, bounced, and other non-engaging email addresses from your email list. Proper email list hygiene will help you:

For more detailed advice about when and how to clean your email list, read the following 5 tips.

1. Define how often you need to clean up your list

Deciding how frequently you will scrub your email list will depend on certain aspects of your program. Generally, we recommend every six months for most email programs. Larger email lists may benefit from more frequent list cleaning, while smaller ones may not require the same level of rigor.

As you review your engagement metrics after each send, you will gather a picture of how healthy your list is overall, and how often you need to address list cleaning.

Whatever frequency you decide is best, it’s important to stick to your cadence. But revisit your cleaning frequency each year and determine if you need to clean your list more or less often.

Bonus tip: don’t purchase lists from third-party vendors…or anybody ever. While you may reap some immediate, short-term benefits, the majority of the list file won’t earn you much value. And you may even find yourself on a deny list as a result.

Because of the nature of these lists, these users are more likely to hit the spam button first. Neither of these outcomes will help your email program. For more reasons why you should never purchase an email list and some alternatives, check out 3 Reasons You Shouldn’t Buy Email Lists.

2. Remove role accounts

Role accounts are emails representing a group or alias–think @support, @info, etc. These emails do not represent individuals and, as a result, are not checked or read very often. When the employee who did check that email alias leaves a company, whoever steps into the new role did not opt to receive these emails and may decide to mark your email as spam.

Pro tip: The SendGrid Email Validation API can actually check for role emails and automatically remove them from your list. Learn more about the Email Validation API.

3. Remove bounced and invalid emails

Most systems automatically remove hard bounces after two tries–and that is a good thing. You don’t want to continuously mail to invalid email addresses because this can have a negative impact on your metrics, especially your delivery rates.

But, in some cases, invalid emails are harder to identify. For cases of suspected bounced emails, you can leverage the SendGrid Email Validation API, which will show exactly which emails are likely to become hard bounces. You can then keep an eye on them and eventually remove them if you need to.

4. Remove unengaged recipients

Unengaged recipients can be the ones that sting the most to remove. But don’t take low engagement personally. Think of how many emails you’ve signed up to receive but never get around to opening and reading!

Although providing an unsubscribe link in your emails is required (by law and by all reputable ESPs), a lot of times, people may not get around to unsubscribing. If a few months go by and the recipient hasn’t opened any of your emails, it’s time to remove them from your list.

ISPs, such as Gmail and Yahoo, are looking at engagement metrics to determine delivery. Don’t give them more reasons to not inbox your messages. If you’re worried about your unsubscribe rate, check out How to Remedy a High Unsubscribe Rate.

5. Confirm email subscriptions

There are several ways to confirm email addresses upon signup. We recommend providing a double opt-in method because it’s the best way to ensure that the subscriber truly wants your email.

Double opt-in signup requires the subscriber to enter their email on your signup form, and then to confirm once more (usually a confirmation email with a link that they need to follow to finish registration).

Double opt-in may demand a little more work on the user’s end, but it is worth it for both the sender and recipient because it automatically helps purge bad email addresses from your list immediately.


Given that traditionally 15% of email goes undelivered, you want to make sure you follow the best practices–including email list hygiene–that will get you to the inbox. Cleaning your email list on a regular basis will prove to be an effective lever for improving your email engagement, sender reputation, and your resulting deliverability rates.

If you need a refresher on additional email delivery best practices, download our free Email Deliverability Guide. It contains everything you need to know about delivering email through your web application.

With more than 15 years of experience, Carly Brantz is an email deliverability and inbound marketing veteran. As the VP of Revenue Marketing at SendGrid, Carly empowers her team to transform marketing from a cost center to a revenue generator. With a key focus on funnel optimization, Carly leads the team responsible for content creation, lead nurturing, SEO/SEM, and website optimization. An accomplished speaker, Carly shares her email delivery and revenue marketing tactics as a headline speaker on SendGrid’s international roadshow as well as other Marketing conferences.