I have a query which returns multiple results with just data in one column as different for a particular report number. I want to group the results for one report number and sen
I believe your actual problem is that you're using pound signs in the group attribute.
group="#investigation_id#" should be group="investigation_id"
--Edit--
This below answer is moot as the OP was misleading.
I think this is because you do not need cfoutput tags inside the cfmail tag. It's odd that it causes a mail error, though.
anyway...
I would try using cfsavecontent then output the variable in the cfmail.
#action_who_email#
Report ID: #report_id#
Report Number: #report_number#
investigation id: #investigation_id#
Action Who :#action_who#
Action What: #action_what#
Action When: #action_when#
Action type:#action_type#
Action Complete Date: #action_complete_date#
#mailBody#