Posted by techinmay on Nov 04, 2025
Dealing with duplicate emails in Outlook is frustrating - it's cluttering your inbox, wasting memory, and slowing down Outlook performance. Whether the same message is appearing multiple times or recurring from syncing, there's a way to help you track down the cause so you can keep your inbox clean. In this blog, we'll show you how to stop duplicate emails in Outlook, cover the core causes, and provide practical guidance for Outlook duplicate mail prevention.
Reasons Why Outlook Sends or Displays Duplicate Emails?
Here is a quick overview of potential reasons Outlook might send or show duplicate emails:
Multiple accounts are pulling the same emails.
Errors in mail rules that copy or move emails multiple times.
IMAP or Exchange synchronisation problems.
Antivirus scans that cause emails to download again.
Repeated imports of old PST files.
Errors in the send/receive settings.