Skip to main content

Optimize and clean your contact list to improve email deliverability

Over time, contacts who signed up for your mailing list can lose interest in your content or change their email address. You may also have contacts signing up using email addresses containing typos or that don't exist at all.

Identifying those contacts and blocklisting them on a regular basis will give you better chances at getting your emails delivered to contacts that will actually engage with your content, while cutting your costs. 

Why should I clean my contact list?

Maintaining a clean list of contacts is imperative for good email marketing and has several benefits, such as:

  • Higher engagement rates: Removing unengaged contacts from your list means that you’re sending emails to contacts who are more likely to open your campaigns and click on a call-to-action. Engaged contacts are the ones who matter most and who will have a positive impact on your deliverability and sender reputation.
  • Better chances of reaching the inbox: The better your sender reputation, the more chances that your emails reach your recipients’ inboxes. Sending emails to engaged contacts will reduce by a lot the risk of landing in the spam folder of your recipients.
  • Reduced sending costs: By cleaning your email list, you'll send fewer emails and these emails will reach engaged contacts. 

Signs that you need to clean your email list

We recommend you clean your email list at least once a year. However, when looking at how often to clean your lists, your email metrics are also a good indicator to know it's time to clean your email list. To see how your email campaigns performed, you can check the metrics available in your campaign reports.

Here are some signs that you need to clean your email list:

  • Decreased engagement, such as lower open and click rates.
  • Increase in soft and hard bounce rates.
    💡 Good to know
    Soft bounces are temporary errors, which means that the contact can be valid even if their email soft bounced (e.g. their inbox is full at the moment but if they clean it, they will be able to receive emails again). But soft bounces can also mean that your sender reputation is bad or that the content of your email has been considered spam. To view the reason why your email soft bounced, check our dedicated section Where can I view the reasons why my email bounced? in the article What are soft bounces and hard bounces?.
  • Increase in unsubscribes and spam complaints.

You also want to consider the number of new contacts being added to your list every quarter: if it’s high, you might want to check your lists more often.

Identify unengaged and invalid contacts

Each contact list is unique, and a contact’s value is relative to your business. However, there are several common characteristics that can help you easily identify your contacts based on quality: engagement, recency, and address type.

If you have used Brevo for a period of time to collect and send emails, your usage data can help you easily filter contacts based on these characteristics - both to identify your lowest and highest quality contacts.

Unengaged contacts

❗️ Important
Following the changes in Apple’s Mail Privacy Protection, Apple Mail users won't be counted in your engaged contacts, as it is not possible to know if they've opened your emails.

After a long period of inactivity (and no response to your re-engagement emails), it’s safe to assume these contacts have either changed email addresses or are no longer interested in your content.

In this case, we recommend you proactively blocklist those contacts. Yes, this means you are willfully shrinking your email list. But these are bad leads or abandoned email addresses, and they’re doing zero good by remaining on your list. If you let them stay, they’ll only damage your sender reputation at best, or become spam traps at worst.

It may feel painful to delete once-promising leads, but practicing email list cleaning like this will result in a better sender reputation, improved email metrics, and higher deliverability rates. 

To find unengaged contacts in your contact list:

  1. Go to Contacts.
  2. Click + Add a filter.
  3. Select the following condition: Contact details > Engagement status > Unengaged.
💡 Good to know
Unengaged contacts are identified by a pre-defined segment. You can update it according to your needs under the Unengaged Contacts setting.

Old contacts

Contacts added to your list over two years ago are least likely to engage with your emails. For a more broad cleaning technique, filter out contacts added more than two years ago. Or, contacts added more than two years ago and who have not made a purchase.

To find old contacts in your contact list:

  1. Go to Contacts.
  2. Click + Add a filter.
  3. Select a condition to filter old contacts, e.g. Contact details > Added date > More than > 24 months.
  4. (Optional) Select an additional condition to filter old contacts more precisely, e.g. Ecommerce > No order placed > In the last > 24 months.

Generic email addresses

Generic email addresses such as, admin@, sales@, noreply@, etc. are often unmonitored and are typically shared by teams. This means they don't correlate to individual people and emails received by them will likely have very low engagement rates.  

To find contacts with generic email addresses in your contact list:

  1. Go to Contacts.
  2. In the search box, type a keyword such as contact, sales, or noreply.

Invalid email addresses

Using a double opt-in subscription form can help keep invalid email addresses, such as fake email addresses or email addresses that contain a typo, off your list. But some invalid email addresses are inevitable and you will need to clean them up.

Purchased/rented lists

Purchased or rented lists don't follow GDPR regulations and are prohibited in Brevo. Most of them contain spam traps and will hurt your deliverability. For purchased or rented lists, we recommend you blocklist all the contacts.

Remove contacts from Brevo

Once you've identified unengaged and invalid contacts, we recommend you blocklist them to prevent sending them emails.

❗️ Important
We highly recommend you blocklist unengaged and invalid contacts instead of deleting them.

Blocklisting those contacts ensures that you cannot accidentally re-import them into your list and send them emails. Also, by blocklisting them, you won't lose any of their data (attributes, history, etc.). To learn more, check our dedicated section Should I delete or blocklist contacts? in our article Delete contacts.

Based on the method used for filtering your contacts, there are two ways you can blocklist them:

Removing contacts filtered within Brevo

  1. While your preferred segment is applied, select the checkbox at the top left of the table and click Select all contacts to select all contacts that match your condition.
  2. Click Blocklist.

  3. Enter the number of contacts that you want to blocklist.
  4. Click Blocklist to confirm.

All the contacts are now blocklisted and won't receive your emails anymore.

Removing contacts contained in a CSV file

If you have curated a list of invalid contacts outside Brevo, it’s important to upload it to your Brevo account as a blocklist. To learn how to blocklist contacts from a file, check our dedicated article Import a list of blocklisted contacts.


Maintain your email lists

Now that you've cleaned your email list, you can try the following tips to maintain its good quality and keep improving your sender reputation and deliverability.

Exclude unengaged contacts from your email campaigns

❗️ Important
If you've already blocklisted your unengaged contacts, you don't need to exclude them from your email campaigns as they can't receive your emails anymore. Excluding unengaged contacts from your email campaigns is useful if you've not yet blocklisted those contacts.

With Brevo, you can easily improve engagement rates by simply excluding unengaged contacts when sending an email campaign. You'll find this option at the To step when selecting the recipients of your email campaign.

To exclude unengaged contacts from receiving your email campaigns:

  1. At the To step of your email campaign, click Advanced options.
  2. Under Filter recipients, select the following condition: Contact details > Engagement status > Unengaged.
💡 Good to know
Unengaged contacts are identified by a pre-defined segment. You can update it according to your needs under the Unengaged Contacts setting.

Segment your contacts

Segmenting your contacts based on their interests and behavior can help you keep them engaged with your content, which will keep your email list healthy.

You can go beyond email engagement-based segmentation and create segments based on:

  • Demographics,
  • Geolocation,
  • Purchase history,
  • Website visits, etc.

Send re-engagement emails

A re-engagement email, also called a winback email, is an email or a sequence of emails designed to re-engage contacts who have stopped engaging with your emails by getting them interested again in what you have to offer.

In an ideal scenario, you win back every single unengaged contact and your contact list has more engaged contacts than before. But even if your re-engagement email doesn't win back every single contact, it’s still useful: you now know which contacts you can confidently remove from your list.

In short, a re-engagement email will not only help you re-engage contacts, but it will also allow you to have a cleaner list, reduce sending costs, get more accurate statistics, and improve your sender reputation.

To learn more about re-engagement emails and see examples, check our blog article.

Reach your contacts at the right time

💡 Good to know
This feature is available for Business and BrevoPlus plans.

With our Send Time Optimization feature, Brevo uses data science to determine when your contacts are most likely to engage and will send your emails at that time to guarantee better open and click rates. It is a great and easy way to engage more with your contacts and improve your deliverability.

Continuously analyze your email metrics

After cleaning up your email list, we recommend you monitor the following email metrics:

  • Email deliverability metrics: soft and hard bounce rates, unsubscribe rate, and spam complaint rate.
  • Campaign engagement metrics: open rate, click rate, and unsubscribe rate.

If you see a drop in engagement and an increase in bounces and spam complaints, it might be time to clean up your list again!

(Advanced) Automate your list maintenance

With Brevo, you can be even more proactive by automating your list maintenance. Here are a few  actions you can do with an Automation workflow to maintain your contact list:

⏩ What's next?

🤔 Have a question?

If you have a question, feel free to contact our support team by creating a ticket from your account. If you don't have an account yet, you can contact us here.

💬 Was this article helpful?

64 out of 116 found this helpful