Lots of problems with the mail app on my new iPad 3 (both before and after upgrade to iOS6). Mail works perfectly on my iPhone 4S (before and after iOS upgrade), but I can't get the same advanced options on the iPad (I like mail to NOT be removed from the server so everything ends up on my desktop eventually) ... the "do not remove from server" option is available in the iPad mail app (but it is on the iPhone)!?
Now there are problems with mail being sent ... but not getting through to working SMTP servers.
Is there any way to remove and reinstall the mail app?