save emails as draft
Add to the Send Email action the option to save an email as a draft (and not send it directly). Or create a separate action Save Draft Email
In this way, you can adapt the email (subject & text) to exactly tailor an email for an addressee before it is sent.
zenphi could even send the person who can change the draft email, an email (with the link to the draft) notifying him that there is a draft email saved