When you log into your Trellus dashboard head over to the Menu on the top right.
If you want to update the business e-mail, select "Business Settings."
In the Business Info card, press Edit.
If you want to change the User E-mail, the one in which you log in with, head back over to the Menu and select User Profile.
Press Edit under User Profile and you can change the E-mail address that you log into your account with.