We have been having an issue for some time. We are on R12.1.1, and Microsoft Exchange 2003. We use Iprocurement, and have it configured so that the workflow notification goes to the approver to approve the internal requisitions. When the approver goes to approve, the approval only works if the email reponse back to the workflow notification mailer is in "rich text" format. Of course this is controlled by the client PC. If something other than "rich text" is selected, the approval email will not work, and the user has to login directly to the applications to approve. Does anyone else have this same issue, and do you have a workaround?