The cerificate settings can be gotten to from the email settings.
Go to your messaging widget. Click on it. Here you will see all your email programs (Gmail, Comcast, Text messaging, Yahoo, etc.). On your button bar click the menu button and you'll get the bottom menu options. Select manage accounts.
Here is the screen where you set your incoming and outgoing server settings. Go ahead and select the email account you are trying to change.
Once ou select one the settings selections come up (General, Incoming Server, Outgoing Server, Other). Click on the Outgoing and you will see the check boxes for certificate verification, Once selected go back to previous screen and do the same for the inbox.
Then you are done.