The need to create and send a Dynamics 365 email allows the email record to be associated with a Dynamics 365, similar to the native workflow send email. ** Currently Flow does not support this.**
I explored using the "create record" action in the email entity. I followed the logic similar to creating this programmatically...first create the email record as "draft", set the required fields including direction and number of delivery attempts = 0. Then the next action sets the email to "pending send", which triggers the email send.
After numerous attempts, and opening a support case, Microsoft indicated this is not supported in Flow.
Note, using Outlook email as workaround does not allow relating to a Dynamics record, and precludes much of the process benefit of the native workflow send email function.
This is very common, simple and useful action in the Dynamics native workflows, and is missing in Flow.