I'm not that clear on your actual business use case, but the below will work.
What Senthil suggests is only applicable for system providers, you don't actually need to do that just use NSQL.
Dave, sadly HTML is not rendered in list views (although there are hacks to make it so)
Here's how to do it
Create an NSQL query like below
SELECT
@SELECT:DIM:USER_DEF:IMPLIED:PROJECT:INV.ID:PK_ID@,
@SELECT:DIM_PROP:USER_DEF:IMPLIED:PROJECT:INV.CODE:PROJECT_ID@,
@SELECT:DIM_PROP:USER_DEF:IMPLIED:PROJECT:INV.NAME:PROJECT_NAME@,
@SELECT:DIM_PROP:USER_DEF:IMPLIED:PROJECT:R.FULL_NAME:MANAGER_NAME@,
@SELECT:DIM_PROP:USER_DEF:IMPLIED:PROJECT:R.EMAIL||'?Subject=Hello%20World':EMAIL@
FROM
INV_INVESTMENTS INV
INNER JOIN SRM_RESOURCES R ON R.USER_ID = INV.MANAGER_ID
WHERE
INV.IS_ACTIVE = 1
AND @FILTER@
Add a link
Create a portlet from the query
Create a virtual attribute in layout
Click Next
Choose Send Email and the link you created and save
Add that virtual image to the portlet and when you click on the link....
email and subject populated as you want