Oracle Apps R12 Workflow Mailer --> Remove the Actions button(Approve/Reject) from the Email

 Remove the Actions button(Approve/Reject) from the Email

Solution:
Open the wtf file in workflow Builder
Right click and add attribute to the message.
Attribute: #WFM_OPEN_MAIL
Default Value: WFMAIL:OPEN_MAIL_OUTLOOK

Save and retest.