Navigate to 'Account Settings \ Profile' and choose 'Email Settings' section.
- Enter default from (sender) email address.
- Enter default from (sender) display name.
- Click 'Update'.
Note: by default every user will user email provider configured by the application. Application manage can allow users to change their email provider. For example, you want to send email from your personal Gmail account. You can do so when your user role is allowed to manage email providers.