Hi everyone. I need some help. In older versions of OSX, when I wanted to sync up the mailboxes between my MacBook Pro and my iMac, I would just copy the data from my iMac onto hard drive from the "Mail" folder in the user library on my Macbook Pro, rebuild them, and it would work. Now, under Sierra, when I do the same thing, the "On My Mac" mailboxes in Mail don't show up, so I can't even re-build them. Clearly, something has changed. Can someone tell me what's changed and how I can do what I used to? Thanks in advance.