Third-party anti-virus software can create this error by interfering with your email sending attempts. You can fix this problem by removing or disabling the apps using the steps below:
- Open the 'Run' window. To do so, press the 'Windows' key along with the 'R' key on your keyboard. Enter the following command in the dialogue box: appwiz.Cpl.
- When you press 'Enter' on your keyboard, you'll be taken to 'Programs and Features.'
- Locate the third-party antivirus product you want to uninstall in the programs list. Once you've located the software, right-click it and select 'Uninstall' from the menu that appears.
- now check if your error is fixed or not
