After configuring outlook 2016 is resending old already sent mails

That's frustrating!

Resending old, already sent emails can be caused by various factors in Outlook 2016. Here are some potential solutions to help you resolve this issue:

  1. Check the "Resend" button: Make sure you're not accidentally clicking the "Resend" button instead of the "Send" button. The "Resend" button is usually located next to the "Send" button in the "Message" tab.
  2. Outlook's "Resend" feature: Outlook has a feature called "Resend" that allows you to resend a message. To disable this feature, go to File > Options > Mail > Send and receive, and uncheck the box next to "Resend unread messages when new messages arrive."
  3. Check for duplicate messages: Sometimes, duplicate messages can cause issues. Try searching for duplicate messages in your inbox using the "Find" feature (Ctrl + Shift + F). If you find any duplicates, delete them to prevent any confusion.
  4. Outlook's "Recover Deleted Items" feature: If you've deleted a message and then resent it, it might still be in the "Recover Deleted Items" folder. To access this folder, go to the "Deleted Items" folder, right-click on the message, and select "Recover Deleted Items."
  5. Check for add-ins: Add-ins can sometimes interfere with Outlook's functionality. Try disabling any recently installed add-ins to see if they're causing the issue. To do this, go to File > Options > Add-ins, and disable any add-ins that you don't need.
  6. Outlook's "Send/Receive" settings: Ensure that your "Send/Receive" settings are correct. Go to File > Options > Mail > Send and receive, and make sure that the "Send and receive every" option is set to a reasonable interval (e.g., every 15 minutes).
  7. Check for Outlook updates: Ensure that you're running the latest version of Outlook 2016. You can check for updates by going to File > Office Account > Update Options > Update Now.
  8. Reset Outlook's cache: Clearing Outlook's cache can sometimes resolve issues. To do this, go to File > Options > Advanced, and click on the "Reset" button next to "Reset Outlook data files."
  9. Check for conflicts with other email clients: If you're using multiple email clients or accounts, it's possible that there's a conflict causing the issue. Try closing other email clients or accounts to see if the problem persists.
  10. Reinstall Outlook: As a last resort, you can try reinstalling Outlook 2016. Make sure to back up your data before doing so.

If none of these solutions work, you may want to consider seeking assistance from Microsoft Support or a professional IT expert.