I currently have an Email Alert setup as the output from a Workflow when a new record is created. This is all working fine.

However, I would like to be able to change the 'from' email address.

When I edit the Email Alert, the only option I have is 'Current User's Email Address'

This results in the from email being...

no-reply@salesforce.com on behalf of MyName [ my_email_address ]

Ideally I would like this to be 'no-reply@my_company_domain'