Do you get an error? Is there something in the logs?
This is not much to go by... The standard SMTP settings you've input should for a Google For Work email address.
Hi Kevin, make sure your firewall is not blocking port 587. Here's an article explaining how to test smtp with TLS (replace port 25 with 587): https://scottlinux.com/2014/06/05/check-for-smtp-tls-from-command-line-with-openssl/ . Run this on your Tableau Server box to ensure that you can connect.