I have 2 gmail accounts and since I am on the PC for most part of the day, I keep it on. Gmail updates my mail and I see it almost as soon as I receive it
Also my Yahoo account is checked atleast 10 times a day
I am very fond of writing and receiving letters from my friends. I have 5 email accounts at that moment. But I prefer to use Google mail best of all. I check it 3 times a day.