Rails 4 Net::SMTPAuthenticationError: 535 #5.7.0 Authentication failed

Try adding openssl_verify_mode => 'none' to your action mailer settings:

config.action_mailer.smtp_settings = {    :address   => "smtp.school.edu",    :port      => 25,     :enable_starttls_auto => true,     :user_name => "account@school.edu",    :password  => "mypassword",     :authentication => 'login',    :domain => 'http://myapp.herokuapp.com/',    :openssl_verify_mode => 'none'}

Granted, we are using Rails 3, but this worked for me. The issue for us was that our certificates are self-signed and the library Rails uses considers that to be a problem.Here is an article that talks about the option.

Should ":domain" point to "school.edu" instead of "herokuapp.com"? I know when you set smtp for gmail via action_mailer settings, you have something like:

config.action_mailer.smtp_settings = {    :address              => 'smtp.gmail.com',    :port                 => 587,    :domain               => 'gmail.com',    :user_name            => 'example@gmail.com',    :password             => 'example_password',    :authentication       => 'login',    :enable_starttls_auto => true  }

Create a file setup_mail.rb in the folder config/initializers/ and put the code:-

ActionMailer::Base.delivery_method = :smtpActionMailer::Base.perform_deliveries = trueActionMailer::Base.smtp_settings = {  :address   => "smtp.school.edu",  :domain => 'myapp.herokuapp.com',  :port      => 25,  :user_name => "account@school.edu",  :password  => "mypassword",   :authentication => :plain,  :enable_starttls_auto => true}ActionMailer::Base.default_url_options[:host] = "myapp.herokuapp.com"