In order to get the full options for the Send Email window when running this via a linked action you need to add a question mark (?) into the units option. To achieve this, please follow the steps below:
Enter Workflow Maintenance and locate the affected Linked Action.
Click Update and click on the Maths Editor Icon (Jigsaw Piece).
Ensure the Cost units is followed by a (?). An example of this can be seen below:
SEND E-MAIL (NONE) AT (Main) DICTATED TO (CLIENT) COST UNITS (?) CASE ( CURRENT-CASE )
Click Accept on the Maths Editor, and click Save in Workflow Maintenance.