To stay organized, you may need to mark a conversation as unread to come back to it later. Here is how to do it?
How to manually mark the conversation as unread?
On conversations assigned to you, select the conversation you want to mark as unread, and click on the unread icon.
Who can mark the conversation as unread?
Only the user assigned to the conversation can mark it as unread.
Read this article to learn more about the unread status