How do I send plaintext email? I've been using a combination of drupal_mail() and Mimemail to send out HTML formatted email; it's working fine.  However, in some circumstances, I also need to be able to send out plaintext email, not an empty HTML template, but a completely raw, plaintext message.
I can't figure out how to disable Mimemail for these messages, while leaving Mimemail in place for the others.
How might I be able to do this?
I've spent some time trying to achieve the same goal.
I didn't find a lot of documentation on MimeMail module, I inspected the code and found a solution :
  $message = drupal_mail('my_module', 'my_module_key', 'email@mail.com', $language,
    $params = array(
      'subject' =&gt; $subject,
      'plain' =&gt; TRUE,
      'plaintext' =&gt; $mailBody,
    ));

You just need to use 'plain' =&gt; TRUE and put your mail content in 'plaintext' =&gt; $mailBody