Is there a way to setup Yahoo mail for push with iOS5?
Yes Yahoo mail supports push, but failing sometimes. This is how to enable it:


Go to "Settings->Mail, Contacts, Calendars"
Tap "Fetch New Data"
Slide "Push" to ON (you can select Fetch period whatever you like)
Also from "Fetch New Data" page, tap "Advanced" and see that Yahoo! mail account has Push text on the right


It is easy to do, but sometimes Yahoo push just doesn't work.