You can quickly create an event from any email by using More > Create Event
You can create a new event from an email to keep all the relevant details from the email in the task.
To create an event:
Click on the More button
Select "Create event"
The event you create will have a "related email" link so you can easily refer back to the email.
You can also use this method to create a Task from an email (Create a task from a email)