I have the answer!! I use a service called nuevasync for imap of my business mail on my WP8. I have used it on WP7 to. It works great. It costs a few dollars ($30??) but it works awesome for imap. And you can set it up as an Outlook account on your phone and get mail as it arrives.
There seems to be a limitation on the number of push accounts you can have on W8 both the phone and Surface will only let me set two accounts up with Push and the rest need a interval setting. I rally hope they address this with a future update.
When setting up a gmail account you are giving two options “email only” or “email, contacts and calendar.” If you select the email contact and cal, you get to select push. If you select email only it sets it up smtp, which only gives you “every 15 minutes.” select the second option and just leave contacts and cal unchecked and all will be well.
I can confirm that the solution Mike posted works for me. I initially set up my Gmail to do email only and then found that tip and changed it to email, contacts and calendar and now I can select 'as items arrive'.
Did anyone find a solution to this. I am using a custom mail server controlled via cpanel. Can't get wp8 to recognize push. I've tried both pop and imap. At the moment I think its added as imap. Anyways, not having push from these email accounts is driving me nuts as I use the domain for freelance.
wp8 does not support imap push. Probably never will. Windows 8 does support push mail on IMAP (as well as server search). So, it is not like MS doesn't know how to do it. It just won't do it to push its EAS.
Well MS in my opinion is a pain in my arse and should get slapped in the face with a raw fish repeatedly. They market their phone as the new Blackberry for business users but they couldn't replace the business market with this kind of attitude if their life depended on it. I am an advid MS fan...stuck with them all these years but I am sick and tired of getting crapped on by stupid decisions.
Honestly, I am kind of excited to see Steve Ballmer retire. I think after Win8 (on the PC side), MS needs some changes.