Workato's Mail app is convenient for sending out automated emails, but will be sent from firstname.lastname@example.org.
Emails from custom addresses (or customized otherwise) can be achieved using other app connectors such as Gmail or HTTP.
Using the Gmail > Send email action, you can have an email sent from your gmail account. All you need to do is to make the necessary connections to your gmail account that you want to use.
HTTP (Advanced, API knowledge required)
If you want to use other email clients, you may use our HTTP connector provided they have an API that meets our system's requirements. More on HTTP here.