Mine is set to check for mail every 5 minutes, but I hardly ever have it open that long. I start it up 5-10 times/day. My wifes is set to check every 30 minutes, she checks hers at least that often. The auto check settings shouldn't have anything to do with being locked out today. I checked my email once and was locked out within 10 minutes of starting up my computer. No other computers were even running here for at least 8 hours prior to being locked out.