It may be because of the email service you use. Google and AOL now have greater authentication requirements when using third-party application like Elements. See this thread for some explanation of how to use gmail.
- if it's Windows 10, is it the 32-bit or 64-bit version?
- in Edit > Preferences > Sharing what options are you given for the Email Client under Email Settings?
- which Email Client do you use?
The reason I'm asking is that these options all depend on your system set up. I'm running an old copy of Elements 10 on a Windows 10 64-bit system, so that means I've only got the defunct Adobe Email Service as an option.