Adding/editing an email address for a customer is easy!
FROM THE WEB APP
Step 1: Go to the 'Client' menu
Step 2: Click on a customer to edit.
Step 3: Click 'Edit'
Step 4: Under a contact click 'Add Email' or 'Edit'.
Step 5: Done.
FROM THE MOBILE APP
Step 1: Tap on Menu > Clients > Select a customer to edit.
Step 2: Tap on the contact name you want to edit.
Step 3: Tap 'New Email'
Step 4: Optional: Tap an existing email address to edit it.
Step 5: Done