It is possible to drag and drop images into the email template field, but it is not an ideal solution. In the template, you can only cc teammates, but at send time, you can type in any custom email address you'd like. To do this, you can swap the email address in your profile and confirm it via your email inbox. None of your previous emails will be impacted, and the links will all still work. It is highly recommended that you connect a Gmail or Microsoft account so that your emails will go through there. Once you've connected an account, that will be your "from" address, no matter which one you use to login. To change the email address, go to the Integrations page, hit the trash can icon, then reconnect the new email.