title: Error in email configuration for Redmine Application
body: <p>My configuration file contains the following code:</p>
  
  <pre><code>production:
      email_delivery:
         delivery_method: :sendmail
  development:
      email_delivery:
         delivery_method: :sendmail
  </code></pre>
  
  <p>But I'm still getting the following error while running Redmine application in production mode.</p>
  
  <pre><code>  NoMethodError (undefined method `error' for 0:Fixnum):
    app/models/mailer.rb:431:in `deliver_mail'
    app/models/mailer.rb:86:in `block (2 levels) in deliver_issue_edit'
    app/models/issue.rb:826:in `each_notification'
    app/models/mailer.rb:85:in `block in deliver_issue_edit'
    app/models/journal.rb:77:in `block in each_notification'
    app/models/journal.rb:75:in `each'
    app/models/journal.rb:75:in `each_notification'
    app/models/mailer.rb:84:in `deliver_issue_edit'
    app/models/journal.rb:190:in `send_notification'
    app/models/journal.rb:54:in `save'
    app/models/issue.rb:1515:in `create_journal'
    app/models/issue.rb:165:in `create_or_update'
    app/controllers/issues_controller.rb:478:in `block in save_issue_with_child_records'
    app/controllers/issues_controller.rb:466:in `save_issue_with_child_records'
    app/controllers/issues_controller.rb:188:in `update'
  </code></pre>
  
  <p>I have no clue about why I am getting this error and I have also checked the configuration against Redmine documentation and action mailer configuration. I still can't figure out the cause.
  Has anybody faced a similar issue?</p>