Change the hostname as like

hostname=localhost

Then try to send mail.

I am giving you few hints. Think those will solve your issue.

• 1. Change the hostname, like

  hostname=localhost

• 2. Go the below link and click Turn on https://www.google.com/settings/security/lesssecureapps
• 3. Check the file TLS_CA_FILE exits or not.

Then try to send mail.