Any mail service provider that uses Exchange will work. They do exist, but I do not have any specific recommendations. In practice, I do not find push mail to

Any mail service provider that uses Exchange will work. They do exist, but I do not have any specific recommendations. In practice, I do not find push mail to be all that important. Its real benefit, at least theoretically, is in optimization of battery usage by not having to constantly poll for messages, but I do not find it makes much difference on iOS and will perhaps become even less important on iOS 7 as background apps will be more apt to be firing up the radio anyway.