Outlook for MAC - add a folder

Hello josephina32,

Welcome to Apple Support Communities. Are you using the Mac Mail app or a third-party email app? In the Mail app, each email account has a set of standard mailboxes but you can add your own to help organize. The following is from Create or delete mailboxes in Mail on Mac.

"Create mailboxes

1. In the Mail app on your Mac, choose Mailbox > New Mailbox.
2. Click the Location pop-up menu, then choose where to create the mailbox.

• On My Mac: Mailboxes you create in On My Mac are local, meaning you can access them only on the Mac where you created them.
• An account: Mailboxes created on your email account’s Mail server can be accessed on any computer or device where you use the account.

If you choose an existing mailbox as the location, the new mailbox is created within the existing mailbox—like a subfolder.

3. Type a name for the mailbox, then click OK."

If you're using a third-party email app, there may be additional options but you will need to reach out to the developer if you need help with navigating those options. For help getting in touch, check out How to contact an app developer.

Best of luck.