mail folder missing on macbook pro but uploaded in iCloud

Hello! I have all my software updated, using Macbook Pro retina and icloud.

In mail I recently created a new folder from my imac. It appears on the imac and in icloud but I cannot get it to appear in the mail folders (under iCloud/Files, where all my other files are synched).

Any idea how I can get this one folder to sync down to my macbook (it's on my other ios devices).

Help much appreciated. Have searched internet but can't find a fix.

Cheers!