I used Drupal simplenews to send newsletter to all the memebers of my site. It was a real hell of life. It takes thousands of my hours to spend to fix the template but I cant. because it was not a probelm in simplenews.
I used mimemail which create all those problem for me. Mimemail add the site css file in mail body autometically and it does not work that inline css of newsletter in Outlook when you sending newsletter from Drupal system.
Then i found a solution which guide me in the below link: