You can choose which mail folders are synchronized with Outlook but you won’t find this option with the rest of the Gmail account settings in Outlook.
Instead go to the heading of the Gmail account in the folder pane, right-click and choose IMAP folders.
Let’s stop for a little IMAP terminology.
Folders that are synced to Outlook are called Subscribed folders.
Outlook defaults to subscribing all folders, but you can unsubscribe (not synchronize) folders.
Open the IMAP folders dialog then click Query to get a fresh list of all visible Gmail folders. The subscribed tab shows all the folders currently synced, click Unsubscribe for any you don’t want or need offline.
We unsubscribe some large folders with older messages. Other users recommend unsubscribing some lesser used folders to keep the IMAP connection running smoothly.
On the All tab, you can see all visible Gmail folders. Subscribed folders have the folder icon beside the name.
When displaying hierarchy in Outlook, show only subscribed folders
Check this option to keep the Outlook folder pane shorter and neater.
Gmail folders visible in IMAP
Notice above we talked about ‘visible’ folders in the IMAP Folder list? That’s because Gmail has a control to hide folders from the IMAP connection.
The default is to show folders (aka labels) in IMAP connections to outside devices (like Outlook) but it’s possible to hide a folder. Go to Gmail Settings | Labels then look in the right-hand column for ‘Show in IMAP.
Uncheck ‘Show in IMAP’ if you only want the folder to appear in Gmail’s browser system not on external devices.
You might do that for old or obsolete folders you don’t need to appear or sync with devices.
Keep ‘Show in IMAP’ in mind if a folder isn’t visible in Outlook.