Browsing your unread messages from Slack on your desktop lets you catch up on the messages you missed while you were away. From the Unreads view, there are different ways you can take actions on your unread messages:
Jump from the Unreads view to a channel or direct message (DM) to send a new message.
View your unread messages
From your desktop, click Unreads at the top of your left sidebar. If you don’t see this option, click More to find it. Keep in mind that messages in muted or archived channels aren't included in this view.
Tip: If you'd like to show or hide Unreads at the top of your left sidebar, learn how to adjust your sidebar items.
Navigate unread messages
Sort and Filter unread channels
Change how your unreads are sorted to best suit your working style. Click the Sort menu at the top of the Unreads view to sort messages alphabetically, by newest activity, or by oldest activity.
You can also sort messages scientifically, and filter your unread conversations based on your sidebar sections. To filter, click the Filter menu, right next to Sort. On paid plans, you'll be able to filter by each of your custom sidebar sections.
Mark messages as read
Click Mark as Read to clear a channel's messages when you've read them. You can also scroll to the bottom of the Unreads view and click Mark All Messages Read.
If you clicked Mark as Read too quickly, just click Undo to keep those messages in your Unreads view.
When you’d like to come back to a channel's messages later, click the arrowicon beside the channel name to collapse it. Click the icon again when you're ready to view the unread messages.
Refresh for new messages
When new messages become available while you’re viewing the Unreads view, the syncing arrows icon will appear in the header. Click the icon to reveal a fresh batch of unread messages.