When I create a new folder in my imap, my colleague can see it, but if she creates a new folder, it doens't appear on my console. The new folder exists online.

Hi, I have an Imap mailaccount, sharing this account with a colleague. We both have our own device. The documents and folders synchronise perfectly, except for this 1 thing. When I create a new folder in my imap, my colleague can see it, but if she creates a new folder, it doens't appear on my console. The new folder my colleague created, exists online. So there seems to be a security-setting in my mailaccount in not automatically accepting new folders created elsewhere. I have a macbook air and use thunderbird, imap. Who can help me out?