You can actually turn off e-mails coming in.
In "My Trackers" above, click on "Start" ....... at the top on the left side, click on "Account / E-Mail Preferences" - half way down is "SparkPeople Alert Notifications?" Make sure that the box "No" is checked for allow e-mail alerts for trophies etc.
Then at the top of that page click on "Email" - make sure none of the boxes are checked. Make sure that you save the changes.
At the top of that page, click on "Community" - the second one down is "SparkTeams" - you can control what comes in from there, too.
I hope that this helps you do what you need to do!