It would be really great if there was button on the Settings page that would allow us to test the SMTP settings we input. I am going to try to add one in our installation (we're self hosted) using one of the methods found below., but I'm a hack so not sure if I'll get them to work. Thanks!
https://practicalhost.zendesk.com/hc/en-us/articles/201845918-How-do-I-test-PHP-SMTP-functionality-
https://github.com/PHPMailer/PHPMailer/blob/master/examples/smtp.phps