Just upgraded from G S2 to S4. I did the automatic set up for my Pop3 email from att.yahoo.com.
It worked real quick and seemed to do everything ok. Later noticed that I didn't have any of the emails that I deleted on my phone on my home laptop.
The obvlious solution was to look for the option 'leave on server'. I could not find it anywhere.
I deleted the account and did a manual set up. It is one of the options when you do a manual setup. Don't know why you can't change it when you do the automatic setup.
BTW, I was surprised that Walmart had the phone on 4/27, and for about $167.00. No camping out all night was needed