Keep in mind, that is from the Cigars Direct site (CBS Sportsline), not the Yahoo! pool I set up. I agree it is annoying so this is how to get rid of it.
Go to the Cigars Direct bracket.
Click "Options" then "Alerts."
Under "Notifications" change "send notifications" to "no."
That will get rid of the e-mails.
Also, there is a Cigar Geeks bracket on CBS Sportsline. This is from a year ago and is not what we are using this year. I set the pool up on Yahoo!