If Outlook keeps sending the same email twice, thrice, or more number of times, it will become a huge issue like outlook sending duplicate emails. Unless you fix it immediately.
Note: The problem usually occurs in the case of emails with attachments.
You might want to know the reasons why Outlook is functioning in this bizarre way.
The following are some causes for your outlook sending duplicate emails:
How to fix the issue?
Now, continue reading this page to find out how to solve the “sending of duplicate emails” problem in Outlook:
Disabling or Uninstalling your Anti-virus:
When you use IMAP or POP to configure or set up your emails, you will have to concentrate on your server timeout. The server timeout, by default, would have been set to 1 minute. To resolve your issue, you need to increase the server timeout to 2 or 3 minutes. But, please avoid setting this value to more than 3.
The following are some detailed steps to alter your server timeout:
If the issue persists, decrease the email send/receive time on Outlook.