Managing your email lists in Microsoft Outlook can be a challenge at times, especially when email addresses are duplicated in the recipient fields. If you have ever thought, "Does Outlook remove duplicate recipients automatically?" the answer may be shocking to you. In this blog, we will explain how to remove duplicate email addresses in Outlook and share how to manually or automatically delete these duplicate email addresses.

Does Outlook Remove Duplicate Recipients?

No, it does not automatically remove duplicate recipients in Outlook when you add them to the To, CC, or BCC fields. If you add the same email address a second time, the message will be sent to that address multiple times, as it occurs, unless your email server removes them.

Why do Duplicate Email Addresses Occur in Outlook?

• Multiple Imports: Importing the same CSV or contact file multiple times without checking for duplicates!

• Syncing Multiple Accounts: Syncing contacts from multiple email accounts or devices may cause contact overlaps.

• Mistakenly Manually Typed Emails: When a user types in the same email manually multiple times.
  
  

• Copy-Pasting Email Lists: Copy-pasting lists without cleaning up duplicates first.

• Duplicates from Auto-Complete Cache: Outlook's auto-complete feature will save duplicate addresses by extracting up to four versions.

• Using Distribution Lists with Duplicate Members: Adding contacts from multiple groups as they overlap with similar email addresses.

• Duplicated Outlook Data: Corrupted Outlook data files may produce duplicates.

• Restoring Backup Contacts will duplicate: Restoring old backups without merging will duplicate contacts.

• Different variations for the same person: Saving the same email address multiple ways, i.e., John Smith, Jonathan Smith, J Smith.

• Importing from Different Resources: Importing separately from social media, phone contacts, and email accounts will eliminate duplicates.

How to Remove Duplicate Email Addresses in Outlook

Method 1: Manually Remove Duplicate Email Addresses in Outlook

Here are some manual steps for manually removing Outlook duplicate email addresses.

1. Open Outlook and select the People (Contacts) tab.

2. Sort your contact list by email address or name.

3. Manually sort through the contacts and delete duplicates.

As an alternative solution, export your contacts:

• Select File > Open & Export > Import/Export.

• Export contacts to a CSV file.

• Open the CSV file in Excel and use the Remove Duplicates function.

• Finally, import the cleaned file back into Outlook.

Best for larger/more messy contact lists.

Limitations of the Manual Method

Here’s a list of the limitations of remove Outlook duplicate email addresses by the manual method:

• There is no backup facility to restore deleted duplicates if you make an error.

• This is very time consuming and manual process in which person may get tired of removing the duplicate emails one by one.

• Sorting emails manually can miss duplicates that don’t look identical at first glance.

• It’s easy to delete emails by mistake, especially in a large group.

• It requires a lot of effort to go through each folder and identify the duplicates.

Method 2:  Use the Automation Method to Remove Duplicate Email Addresses in Outlook

If you have a lot of email addresses that need to be deleted, third-party tools are available! These tools provide features like scanning in intervals or scheduling scanning and options to customize the deletions — which is helpful for long trigger inbox cleaning.

If you want to prevent these limitations, use an automated method and know how to delete duplicate emails in Outlook.

Use an Automated Method to Remove Duplicate Email Addresses in Outlook

SysTools Outlook Duplicate Remover is a professional third-party tool that can remove duplicates from Outlook data files (PST/OST). It can do what the Outlook add-ins cannot and is also well-suited for cases where you have a large number of duplicates and want better control. 

Key Features of Outlook Duplicate Removing Tool - How It Works:

• SysTools reads both PST/OST files from Outlook and scans for duplicates in your email address to remove them.

• This scanning will review many fields, including subject, sender, date, and attachment for matching.

• You can choose to select one or more folders (Inbox, Sent, etc.) to clean.

• You can choose to delete the duplicates or move them to a folder for review.

• It also supports batch processing of multiple PST files in one location.

• The tool is helpful when data is imported into Outlook or when restoring backups.

• Doing this regularly will help limit the possibilities of slow Outlook performance and storage issues overall.

• It will process mail from your inbox for Outlook 2019, 2016, 2013, or earlier versions.

• It is an effective method of keeping your Outlook inbox duplicate-free!

Guide to Remove Duplicate Email Addresses in Outlook

Here are the following steps: -

1. Install and launch the remover tool.

2. Now, add the PST files, and click on the Add Files or Add Folder button.

3. Click on Open to add the selected PST files.

4. After that, either select Within Folders or Across Folders and then click on the Next button.

5. Now, click on the Destination option if you want to save the file in a different destination.

6. Then click on the next button.

7. Now, you can choose the Apply Filters option, and here you can select the email in which the recipients are categorised.

8. Click on the Next button to start the process of removing duplicates from PST/OST/BAK files.

9. Once all the task is done, click on the home or close button.

Conclusion

To efficiently remove duplicate email addresses in Outlook, manual methods can be tedious and error-prone, especially with a large number of contacts. Since Outlook automatically, using a reliable automated solution is the most effective way to clean your mailbox, eliminate redundancy, and maintain organized communication. The best approach is to use an automated solution that ensures accurate and fast cleanup, making Outlook remove duplicate recipients a simple and stress-free task.