Okay, fair enough. So I now changed it to have it poll every 10 minutes and it's still not pulling emails unless I do a manual refresh. How do I set it to check emails periodically on POP?
It should be checking mail (every 15 by default, or every 10).
If not, the most common culprit(s) are "battery optimizers", built into Android, or preinstalled, or third party.
There is a checklist near the end of the FAQ (which in turn is linked just below, in my signature).