Redmine

i'm using smtp.gmail.com as my SMTP server, but it is not working. when i try to click test email button in admin notification tab
it always showing the error "An error occurred while sending mail (535-5.7.8 Username and Password not accepted. For more information, go to )"
this is my configuration in yml.

email_delivery:
delivery_method: :smtp
smtp_settings:
enable_starttls_auto: true
address: "smtp.gmail.com"
port: 587
domain: "smtp.gmail.com"
authentication: :plain
user_name: "myEmail@gmail.com"
password: "myPassword"

please help, my email username and passowrd.. i have double confirm, its the correct one because its my personal email