Minimum Permissions Needed to Send Pre-Approved Email

This may be an odd question, but would benefit our operational emails greatly. What are the minimum permissions on a user's role that we need in order for a user to be able to execute an email that has already been created and approved?

The reason I ask is that we have emergency communications that we have to send sometimes at hours when our marekting department are out of office and would like to give a minimum permission set to our tech team to send out these communications when necessary. However, we'd like to give them as few other permissions as possible. Since we don't know when or if the email needs to be sent, we can't just schedule it for a specific time ourselves.

So what are the permission necessary if we were to create a new role for this specific instance?

Thanks for any help!