If you're still having trouble, it may be time to change the server settings in your Outlook. This will prevent your email from being sent twice. If you're using a server with a timeout of one minute, you can set it to 10 minutes or more. If you're still having the problem, you can try setting up the timer for 2 minutes. This will allow
Outlook to stop sending duplicate messages
and will prevent the duplicate emails from appearing in your inbox.
See also - https://emailspedia.com/how-to-stop-receiving-duplicate-emails-in-gmail/
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