How To Check For Duplicates In Mailchimp

MailChimp stands out as a widely used email marketing tool enabling companies to distribute newsletters, promotional messages, and various other communications to their subscriber base. A frequent challenge encountered by numerous MailChimp users is dealing with duplicate contacts within their email lists. This article will explore methods to identify and eliminate duplicate entries in MailChimp.

Why Check for Duplicates?

Checking for duplicates in MailChimp is important because it can help you avoid sending duplicate emails to your subscribers. This can be frustrating for your subscribers and may even lead to unsubscribes. Additionally, having duplicate contacts in your mailing list can affect your email deliverability rates, as some email providers may flag your messages as spam if they detect too many duplicates.

How to Check for Duplicates

To check for duplicates in MailChimp, you can follow these steps:

  1. Log in to your MailChimp account and navigate to the “Lists” section.
  2. Click on the list that you want to check for duplicates.
  3. In the “Contacts” tab, click on the “Segments” button.
  4. Create a new segment by clicking on the “New Segment” button.
  5. In the “Conditions” section, select “Email Address” as the field and “is equal to” as the operator. Then, enter the email address of the contact that you want to check for duplicates.
  6. Click on the “Save Segment” button to save your segment.
  7. In the “Segments” tab, click on the name of the segment that you just created. This will display all the contacts in your list who have the same email address as the one you entered in step 5.

How to Remove Duplicates

Once you have identified the duplicates in your mailing list, you can remove them by following these steps:

  1. In the “Segments” tab, click on the name of the segment that you created to check for duplicates.
  2. Click on the “Export” button to export the contacts in this segment as a CSV file.
  3. Open the CSV file in a spreadsheet program like Microsoft Excel or Google Sheets.
  4. Delete all the rows that contain duplicate email addresses. You can do this by sorting the column containing the email addresses and deleting any duplicates.
  5. Save the edited CSV file with only unique email addresses.
  6. In MailChimp, navigate to the “Lists” section and click on the list that you want to remove duplicates from.
  7. Click on the “Import” button and select “CSV” as the import method. Then, upload the edited CSV file that you saved in step 6.
  8. In the “Import Options” section, select “Replace existing contacts with the same email address” as the action to take when importing duplicates.
  9. Click on the “Import” button to import the edited CSV file and remove any duplicates from your mailing list.


Checking for duplicates in MailChimp is an important step in maintaining a healthy mailing list. By following the steps outlined in this article, you can easily identify and remove duplicate contacts from your list, ensuring that your emails are delivered to the right people at the right time.