We are using SBS 2012. we use email message approval process which works fine on desktop PCs. But when we try to access it from iPad/iPhone's Safari browser, the approve / decline buttons are not shown. How can it be done?
Moderated message transport is possible using Outlook or OWA as clients. You cannot do this using iPhone/iPad or any other Exchange ActiveSync based clients. Hence no Approve/Disapprove buttons for iPhone/iPad
You have to ask the end user to use OWA in iPad for message approval.
Microsoft's guidance here: http://blogs.technet.com/b/exchange/archive/2009/06/10/3407662.aspx