I have to turn off the email software Preview Pane so I can highlight the email and then goto View > Message Source before I decide to open it or not.
Whilst it is a workaround, it is not proper, especially with so many fraud/spam/infected emails around.
It's getting worst. You now get emails that don't even say they're from CNET, that's NOT good.
Remember to NEVER open an email from someone you don't know.
This NOW is NEEDED to be addressed. It wasn't taken care of for over a year and now it has gotten out of hand to the point you don't know who the emails are coming from.