Facebook is changing the way messages are displayed for easier communication. Now, when someone sends you a message that is not at least a friend of yours or has your phone number, it will appear as a "message request", which you can choose to accept or ignore.
With the old one system, these messages appeared in a folder next to your “Inbox” titled “Other". It might not look familiar to you because these types of folders (Other, Unread, Archived, Junk) don't appear on the surface work. In general, you would need to add someone as a friend first in order for their messages to appear in your Inbox or on mobile Appliances.
Naturally, no one wants spam messages, so that Facebook states that it will continue to filter messages. The "message requests”Are starting to appear gradually to all Facebook users today.