After sending the reply email from MESSAGE composer window, the message replied is not shown. So I tried below 

return {
            'type': 'ir.actions.client',
            'tag': 'reload'
}

But, after sending the reply mail, it reloads the window and does not highlight the message where I had previously replied.  So, it is difficult to check reply sent.

Is there any other method other than the use of tag= reload?

I checked this link: https://accounts.openerp.com/forum/Help-1/question/How-to-refresh-the-original-view-after-wizard-actions-10268