PST files can become quite large over time, which can create difficulties in handling them. This problem frequently arises due to the identical items, resulting from multiple transfers from different email platforms into Outlook accounts. As a solution, I suggest exploring the benefits of using EmailProHelp Deduper for Outlook. This tool provides a user-friendly way to easily remove duplicate emails, contacts, and other mailbox elements from your Outlook PST, streamlining your email management process. The tool has a range of additional features, which are detailed below:-

• It supports the PST file of All Outlook versions including Outlook 2021.
• Supports all Windows OS inclusive of Windows 11.
• You can also preview all emails and attachments before eliminating duplicate items.
• The Utility has a simple GUI for better performance and quick duplicate removal.