I have just setup a brand new Zoho Mail account. Everything is working fine. I get emails on the iOS app and on the webapp, but I would much prefer getting push active sync mail straight to iOS. No matter what I do, it seems it does not want to authenticate. I keep getting a message as if my credentials were incorrect, I have checked and been careful multiple times and have done these steps at least 3 times:
https://www.zoho.com/mail/help/idevice-access.html