You can connect your Gmail account to any desktop email client that supports it. When you do, all the folders you’ve created in Gmail also sync to your desktop. Not all desktop email clients do but the good ones definitely sync them. This may, or may not be a good thing. All email clients have an ‘All Messages’ or some similarly named inbox where every single email appears. If you want to exclude some Gmail folders from being synced to the client you can. There’s a built-in setting that lets you hide Gmail folders from a desktop email client.
The setting is in Gmail so it doesn’t matter which email client you use. This works regardless if you’re on the old or new Gmail interface.
Hide Gmail Folders
Open Gmail in your web browser. Click the little cog wheel button under your profile picture. A menu will open. Select Settings from the menu.
On the Settings screen, go to the Labels tab. The default folders are listed at the very top so if you want to hide any of them, uncheck the Show in IMAP option. If you want to hide custom folders, scroll further down this same screen and you will see them. Each one has its own Show in IMAP option next to it.
The folders in Gmail aren’t actual folders. They’re basically labels that you add to your messages to keep them organized. Think of them like tags. If you go to a label, you will of course find the marked message there but deleting the label, or hiding it from your email client will not delete any messages.
You can hide the folders/labels but the messages aren’t going to be hidden from the email client.
The labels will still be there in Gmail even if you hide them from the email client. If you want to hide them in Gmail, you can do that as well from this same screen. Each label has a Hide option next to it and clicking it will hide it from the left column in Gmail. Again, no email message will be hidden or deleted. The label will no longer appear but you can still read the messages that have the hidden label from the Inbox inbox.
If you use Hangouts in Gmail, the chats are all saved to their own folder/label. By default, they are not synced to your desktop email client however, you can show it in the client by selecting the ‘Show in IMAP’ option next to the Chat folder/label from this same screen.