Get rid of SMTP Authentication Error in a few easy steps. Here’s a simple code that can help you reconfigure SMTP settings to remove the error.

Net::SMTPAuthenticationError: 535-5.7.8 Username and Password not accepted. Learn more at

from /home/botree/.rvm/rubies/ruby-2.6.3/lib/ruby/2.6.0/net/smtp.rb:981:in `check_auth_response'

Don’t search anymore. You just have to enable the following setting.

Smtp Email

And here is SMTP setting I am using to send emails using Gmail for ready reference

config.action_mailer.delivery_method = :smtp

config.action_mailer.perform_deliveries = true

config.action_mailer.raise_delivery_errors = true

config.action_mailer.perform_caching = false

config.action_mailer.default_url_options = { host: 'localhost:3000' }

config.action_mailer.smtp_settings = {

user_name:      Rails.application.credentials.dig(:smtp, :user_name),

password:       Rails.application.credentials.dig(:smtp, :password),

domain:         '',

address:        '',

port:           '587',

authentication: :plain,

enable_starttls_auto: true


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