Mario,
I agree with you it's one or the other
Write plain text or select an item from a linked feed.
I believe the options are a bit flawed and need's to change.
In the Dropdown, I chose "Input Fields" then "In1" then selected my item Email_To_Send
this then inserts in the body
'Email_To_Send'
but this causes an error when I execute the process
The correct option is to remove the single quotes automatically generated by the dropdown
hence it should be
Email_To_Send
ie without the single quote, this works perfectly
Frank