Lately I rarely consciencely run e-mail in the background. Once I launch it it usually runs until reboot or accidental double-click on the X
If I'm having an e-mail exchange I'll check every few minutes after sending my last reply otherwise it checks every 30 minutes. I found it easier to filter
in what I want than to worry about everything else so I gave up the inbox. I check my friends/family & business folders a few times a day and dump out the other folders once a week or so.