Imap push is enabled but only when on WiFi. For cell I use scheduled mail checks.
I noticed today when I left the WiFi area and the phone switched to cell, Aqua Mail was still using Imap push (visible by the notification status symbol). When I forced a mail recheck the symbol would disappear.
Will try again next time I leave Wifi but thought I should mention it here.
Sent from my GT-I9100