grab the small circle underneath the date of the message to mark the thread unread.
Select any messagethread and snag the gear icon that appears under the date.
Messenger Mobile App
Facebook has two mobile apps: Facebook and Messenger.
Open Facebook in your web browser and select the Messages icon (it looks like a speech bubble) in the top-right corner of the window to see your recently received messages.
Touch and hold your finger on a conversation.
Tap the hamburger icon that appears on the right side to open a menu.
Other options in the menu includeIgnore Messages,Block,Mark as Spam, andArchive.
Select the small circle underneath the date of the message to mark the thread unread.
If you don’t see the message thread you are looking for, click See All in Messenger at the bottom of the screen that lists your recent messages.
Select any message thread and select the gear icon that appears under the date.
