Apple Mail - how to select which Fastmail Folders are synchronised?
 

Running MacOS Sierra 10.12.5 with Apple Mail 10.3

I am trying to setup Apple Mail with my Fastmail account but want to exclude certain large folders on the Fastmail IMAP server from synchronising. In Apple Mail I select my Fastmail Inbox and then right click to select "Account Info" I see a dialog which has a "Subscription List" pane. However, the panel never populates with the list of my Fastmail folders so I can not control which folders are synchronised.

Can anyone provide advice as to how to correct?

That feature of Mail is for subscribing to public or shared folders, not folders in your own account. As far as I know, there's no way to exclude your own folders in Mail.

As I recall, the only partial circumvention is to separate folders you want to see into a nested folder structure (e.g. put them under a top level folder subscribed) and use an IMAP prefix such as INBOX.subscribed. Obviously, this is far from ideal. Unfortunately, most major players do not want standards. Even in the security area, Apple wants to sabotage the standards in the hope of advancing its own proprietary solutions.