Mail notifications to self Net::SMTPAuthenticationError

I am trying to set up a mailer to send myself notification methods. I am currently trying to get the mailer to send myself a simple message when I go to the URL localhost:3000/send_mail

I am currently getting this error:

Net::SMTPAuthenticationError in HomeController#send_mail

534-5.7.9 Application-specific password required


config.action_mailer.raise_delivery_errors = true

host = ‘localhost:3000’

config.action_mailer.default_url_options = { host: host }

config.action_mailer.delivery_method = :smtp

config.action_mailer.smtp_settings = {

address: ‘’,

port: 587,

domain: ‘’,

user_name: ‘’,

password: ‘mypwd’,

authentication: ‘plain’,

enable_starttls_auto: true }


match ‘/send_mail’, to: “home#send_mail”, via: “get”

home controller:

class HomeController < ApplicationController

def index


def send_mail

ActionMailer::Base.mail(:from => "", :to => "", :subject => "Contact request", :body => "test").deliver_now

render nothing: true




The reason you are getting that error is because more than likely you have set up 2 factor authentication with Google/Gmail. So it is saying you need to include a application specific password. In other words don’t use the usual login password, create an application specific password on Google/Gmail and then use that in your smtp settings. Hope this helps.

Mike Riley

Take a look at:


Thank you!! worked like a charm!

thank you!!! worked perfectly!!