Me personally, I wouldn't set it below every hour. If your phone is checking for e-mail it cant receive calls during the process, they would just get voicemail. I leave mine at check manually. soon as you go to look at your inbox it checks to see if you have any mail. checking every 5 min would be pretty much like.. 288? times within a 24 hour period.. chances are all your calls made to you wont make it through....