ActionMailer::Base.raise_delivery_errors = true
ActionMailer::Base.delivery_method = :smtp
ActionMailer::Base.smtp_settings = {
  :tls => true,
  :enable_starttls_auto => true,
  :address => "smtp.gmail.com",
  :port => '587',
  :domain => "domainname.tld",
  :authentication => :plain,
  :user_name => "user@domain.tld",
  :password => "yourpassword"
}