Some common problem with older versions of Outlook or Windows is the lack of support for an encryption method known as TLS v1.2 . If you encounter the following error while trying to send email:
https://jaapwesselius.com/2018/09/23/outlook-2010-disconnected-with-tls-1-2/
To further verify your windows and browser support the latest encryption and security protocols, please visit:
https://www.ssllabs.com/ssltest/viewMyClient.html
Encryption is important to protect your data while being transmitted over the internet.