Why is my label (mailbox) disappearing from my sidebar?
It's because you enabled the Watch option on the label or mailbox, which automatically hides it when there are no unread conversations left in it.
Here are the steps to remediate the issue:
- Click the + More option in the sidebar
- Open the label or mailbox
- Right-click on it, and uncheck the Watch option:
Or simply hover the eye icon and click Stop watching.