Siri has always been able to send email and with the proper wording you can give the Assistant all the information in one go and Siri will produce the message. However, this process can be problematic if the message is long or uses words Siri isn’t familiar with. This can lead to a lot of fiddly editing in the Siri interface.
With Shortcuts you can gain much greater control over this whilst still using the Assistant.
I made this Shortcut to accomplish this:
https://workflow.is/workflows/a811bfe71103423a9bbfba2b3f691c11
Hope it’s helpful. Happy to hear about any improvements people have.
Thanks, Brian