nice question:- i check my mails 2 times a day.....in the morning and again in the evening And replies in this thread are music to e-mail service providers.
Put them all into Outlook/whatever e-mail client you use or redirect then into just one single e-mail account
I have used one email address for all of my sites. I use Thunderbird (gmail pop account). I don't know how much times a day I check my email, because Thunderbird is always ON whenever I am online.