title: ActionMailer 3 error - undefined method `encode!' for "Welcome":String
body: <p>I'm getting this error while sending mail to the registered user in rails 3:</p>
  <p><code>undefined method 'encode!' for &quot;Welcome&quot;:String</code></p>
  <p>I have the following code</p>
  <pre><code> @content = content
   mail(:to =&gt; content[:email], :subject =&gt; &quot;test&quot;)
  </code></pre>
  <p>If there is a subject then above error message displaying, if I remove the subject content</p>
  <pre><code>@content = content
  mail(:to =&gt; content[:email], :subject =&gt; &quot;&quot;) no error message sending with out subject  
  </code></pre>
  <p>I'm using:</p>
  <ul>
  <li>Rails version 3.0.1</li>
  <li>action mailer 3.0.1</li>
  </ul>