Issue sending emails in Outlook after Win 10 upgrade ?

to solve the issue follow the below steps

1. Firstly, close Outlook, and then hit the Windows key and type cmd into the search box (do not press enter).

2. Right-click on the application and select “Run as administrator”
Please note that you may need to enter your system’s administrator username and password.

3. You should now have a black window with a prompt to type a command.
Type the following command and hit Enter:

sfc /scannow

The sfc /scannow command will scan all protected system files and replace corrupted files. This should then resolve this issue and you can successfully send emails using Outlook.