The 'Mark all threads as read' is introduced to eliminate unnecessary clutter in the inbox. If you had a problem dealing with umpteen messages in the inbox, 'Mark all threads as read' is a magic wand which declutter your messages.
To do so, head to your inbox and click the dropdown. Click 'Mark all threads as read'. Refer the below image for the same.
The below demo is a testament to its functionality.
Let's understand the feature better with the use of a scenario.
Noah is a UX/UI designer at a firm. He has been on leave for a couple of days. Now, that he is back, his inbox is flooded with messages. He has read the important ones.
With the 'Mark all threads as read' feature, he does not have to manually mark each message as read. All he has to do is click the dropdown in the inbox and further click 'Mark all threads as read'.
If you have any questions regarding the same, reach us at Zapty Support and we would be glad to help.