Attempting to send email in ASPNET MVC. Cannot connect to SMTP server

The SMTP host is up and running: https://mxtoolbox.com/SuperTool.aspx?action=smtp%3a173.194.69.109%3a587&run=toolpage

 

Error 10600 is either credentials or a port block (local firewall problem). Try to deploy the application to the server and see if it works there. And check credentials.
You can also debug with SMTP4DEV which makes a fake local SMTP: https://github.com/rnwood/smtp4dev/releases/tag/v2.0.10

Since you are trying to connect the gmail, check out this post:
https://stackoverflow.com/questions/7982810/how-to-use-gmail-smtp-in-asp-net-form