I have it set to check every hour and it never notifies me and never works.
If I go in and manually check it, it works - sometimes. Otherwise it doesn't.
For example...this morning, I pick up my phone and check my notifications...nothing whatsoever from the email client. I go into the email client, no messages there either. I manually "load more messages" and bam I have 8 emails ranging from 1 hour old to 7 hours old, none of which that got downloaded throughout the night.
I can't forward my mail from my IMAP to GMail even if I wanted to, which I don't. That's not a solution, that's a workaround.