Remove duplicates in Office 365

Duplicate emails in Office 365 mailboxes can quickly clutter your inbox, reduce productivity, and consume valuable storage space. These duplicates often result from syncing issues, improper mailbox imports, or repeated email forwarding. Over time, they can lead to confusion and make email management more challenging for both users and administrators.

EdbMails Office 365 Duplicate Remover is a specialized tool designed to detect and eliminate duplicate emails from Office 365 mailboxes. Using advanced filtering and matching algorithms, it scans mailbox folders and identifies duplicates based on parameters such as subject, sender, date, and time. EdbMails ensures safe removal of redundant messages without altering or impacting your original data.

Whether you're cleaning up after a migration, solving sync errors, or just maintaining your mailbox health, EdbMails makes the process fast, accurate, and hassle-free. In this guide, we’ll walk you through the step-by-step process of removing duplicate emails in Office 365 using EdbMails, helping you streamline your mailbox and reclaim storage space effortlessly.

1. Office 365 Duplicate Removal Planning

   Duplicate emails in Office 365 can clutter user mailboxes, reduce productivity, and consume valuable storage. To ensure a smooth and accurate cleanup process, it’s important to plan properly before removing duplicates.

   Identify the source of duplicates

   • Determine whether duplicates were caused by PST imports, mailbox migrations, Outlook sync issues, or misconfigured rules.
   • Check if users are accessing the same mailbox from multiple devices or apps that may cause conflicts.

   Assess the extent of duplication

   • Review affected mailboxes to estimate the volume and severity of duplicates.
   • Prioritize high-usage folders such as Inbox, Sent Items, and Archive.

   Define the scope of cleanup

   • Decide which mailboxes and folders need to be scanned to avoid unnecessary processing.
   • Identify criteria for duplicate detection — same subject, sender, timestamp, body content, or attachments.

   Plan the duplicate handling method

   • Choose how duplicates should be managed:
     1. Soft Delete : mark as deleted but keep for recovery.
     2. Hard Delete : Delete duplicates permanently.
     3. Move to Deleted Items : safer option for verification before final deletion.

   Prevent recurrence

   • Review and adjust Outlook rules, mailbox forwarding, and sync settings.
   • Archive or move old emails to reduce clutter in primary folders.
   • Educate users about avoiding multiple imports or manual PST merges.

   Use professional tools

   • Employ a specialized solution like EdbMails Office 365 Duplicate Email Remover to automate scanning and removal.
   • Run tests on a pilot mailbox before scaling to the organization.
   • Ensure a detailed report is generated for audit and confirmation.

   Verification and review

   • After planning, perform a controlled cleanup and review the results.
   • Confirm that no critical emails are lost and only duplicates were removed.

2. Pre-Duplicate Removal

   Before removing duplicate emails:

   • Ensure that you have a global admin account with a mailbox for Auto Registration of EdbMails application on your Entra ID (Azure Active Directory). However, you can use either a global admin account or any user account with full access rights in the Manual Registration method.
   • Ensure that your network and bandwidth meet the requirements for the migration.

      Refer to the following links for network and migration planning, performance factors and best practices.

   • Review Outlook rules, forwarding settings, and sync policies to stop duplicates from reappearing.
   • Decide on the removal action : delete permanently, move to Deleted Items.

3. Steps to remove duplicates in Office 365 using EdbMails

   Step 1: Download and Install the EdbMails application

   • Download and install the EdbMails application on your computer running on Windows OS.

     

   • Log in using your registered email address and password or choose the 'Start Your Free Trial'.

     

   Step 2: Select Duplicate Remover product

   • Select the ‘Remove Duplicates from O365. Exchange. IMAP’ option

     

   • Select ‘Remove duplicates from Office 365 mailboxes’ option

     

   • You can keep the default job name or click ‘New Job’ to change the job name

     

   • Choose your preferred options from the settings, then click ‘Next’ to continue.

     

   Step 3: Connect to source Office 365 server

   • Click the 'Add New Connection' button to establish a connection to the source Office 365 server. To use an existing connection, simply select it from the list and click 'Connect to Existing' to proceed.

     

   • Choose the required connection methods and click 'Next'.

     

   • Select one of the authentication methods and click the ‘Login’ button to continue.

     

   • Authenticate on Microsoft sign-in page.

     

   • Choose one of the methods to load the mailboxes

     

   • Select the required mailbox and click ‘Next’

     

   Step 4: Verify source mailboxes

   • Verify the mailboxes and ensure the ‘Action’ is set to ‘Remove Duplicate’

     

   • Click the ‘Start’ button to initiate remove duplicate process.

     

   • That’s it! You can monitor the progress during the deduplication process, and a confirmation message will appear once it’s complete.

     

4. Post-Duplicate Removal

   After the cleanup is complete:

   • Review the detailed report from EdbMails to confirm the duplicates removed.
   • Check critical folders (Inbox, Sent Items, Archive) to ensure accuracy.
   • If duplicates were moved to Deleted Items, review them before permanent deletion.
   • Monitor the mailbox for a few days to ensure no new duplicates appear.
   • Document the cleanup process for audits or future maintenance.

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Additional resources:

• EdbMails Office 365 Duplicate Remover
• Steps to remove duplicates in Exchange server
• Steps to remove duplicates in IMAP server