Root I'm confused, ES File Explorer Help?

[m6284505]

So I downloaded a mail+nonprime.apk from XDA so I can use Exchange with no security.

Super SU shows ES File Explorer has been granted Root access. I deleted all my mail accounts and wiped data via Titanium.
I opened ES File Explorer and turned on Root Explorer and rebooted the phone. I went into ES, went to /system/app and tried to delete mail.apk and it won't let me. It says read-only file system. I can't replace it with the renamed, modified mail.apk. I went to the file properties and put a check in every box in permissions and still cannot delete it.

What do I need to do?!!? Dang it!!!!

 

[m6284505]

I tried to do it via ADB and that screwed it up. Now I have no mail app on the phone and if I try to run the original mail.apk it says app not installed. I try to run the email.apk that I put in there via adb and that fails, too.

 

[BRAINZ2013]

Es should say rw read/write . not ro now if you set the permission on the mail apk you should have access again . but change to rw.