Redmine

Very Need this issue!!

A workaround for this could be to install a local MTA on the machine running Redmine and let it relay to the Exchange server.
Here's a how to I found for Postfix as MTA and NTLM-authenticated client for relaying mail (not for Redmine, but for Trixbox): Getting trixbox 2.6.2.2 Postfix to relay through Exchange Server 2007

This issue resolve problem http://www.redmine.org/boards/2/topics/4969

Please also read :
http://www.breckenedge.com/2011/07/configuration-of-ruby-on-rails-actionmailer-for-microsoft-exchange-smtp/

+1 !
I also would need this feature...

Sending mails via smtp using an exchange server (auth-method ntlm) is not possible at the moment. Many companies (as ours) use exchanges based email services and if redmine supported ntlm this would help us (and many others) very much.
Maybe redmine will support ntlm auth method in one of the next releases?

The solution that worked for me :

1. Create a Gemfile.local containing "ruby-ntlm" :

# echo 'gem "ruby-ntlm"' > /path/to/redmine/Gemfile.local

2. Install the Gem with :

# bundle install

3. Add the following line to /path/to/redmine/config/environment.rb

require 'ntlm/smtp'

4. Configure your smtp connection in /path/to/redmine/config/configuration.yml

# default configuration options for all environments
default:
  email_delivery:
    delivery_method: :smtp
    smtp_settings:
      address: exchange.domain.com
      port: 25
      domain: domain.com
      authentication: :ntlm
      user_name: 'user'
      password: 'pass'