¨504 5.7.4 Unrecognized authentication type¨ Rails app to MS Exchange

Question

My question is very similar to this one but the accepted answer has not solved my problem.

Here is what I have for my config file:

# Config for mailserver
config.active_support.deprecation = :notify
config.action_mailer.delivery_method = :smtp
# SMTP settings for Exchange server
config.action_mailer.smtp_settings = {
  :address            => 'outlook.<domain>',
  :port               => 25,
  :authentication     => :ntlm,
  :user_name          => '<userName>@<domain>',
  :password           => '<unencryptedPassword',
  :domain             => '<domain>',
  :enable_starttls_auto => true
}

I have tried setting up a relay connector on the Exchange server to accept requests from the IP address of my application.

Also, my original problem was before I used NTLM and my config file looked like so but I got the same error:

# Config for mailserver
config.active_support.deprecation = :notify
config.action_mailer.delivery_method = :smtp
# SMTP settings for Exchange server
config.action_mailer.smtp_settings = {
  :address            => 'outlook.<domain>',
  :port               => 25,
  :authentication     => :login,
  :user_name          => '<userName>@<domain>',
  :password           => '<unencryptedPassword',
  :domain             => '<domain>',
  :enable_starttls_auto => true
}

I have successfully been able to send email using Gmail's SMTP server so I don't think it's the Rails side, but the Exchange server not recognizing my application.

Answer 1

Turns out I was using the wrong authentication because the Exchange server doesn't require any sort of authentication (mainly so printers, faxes, etc. don't need to authenticate).

Here's the resulting settings I used:

config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
  :address              => 'outlook.<domain>',
  :port                 => 25,
  :authentication       => :plain,
  :enable_starttls_auto => true
}