How do you disable mail marking messages as read?
I use the unread status of emails to show they still need my attention (after I have viewed them in preview).
Apple mail marks them unread automatically. Although there is an 'unread' button I can then click, I don't want to do this extra step.
How do I disable this frustrating behaviour? I have googled this over the years to find nothing. I want to go back to using Apple Mail but every time I check to see whether this behaviour has changed in the last year, it hasn't.
Any clues would be greatly appreciated.
iMac (21.5-inch Late 2009), OS X Yosemite (10.10.4)