Are you certain that you are receiving all the messages on Facebook and nothing is being filtered out? If you do believe that, then you are in for a surprise as some messages are diverted to a special folder in the message requests box that many people overlook during their use of the app. The messages in this category don’t ring a notification because it is from a person who is not in the contact list of the user. This feature is easily accessible on PCs as when you open the message toolbar, you will get an expanded menu showing all the messages and the message requests option on the top right. But, when it comes to smartphone app messenger, the message requests aren’t readily available.
Previously, it was a folder named “Other” that contained all these messages but now Facebook has changed it. To view these messages on the phone, now you will have to open the app and look for the bottom right corner where “settings” option will be present. From there you will be redirected to the in-app profile page. From here you can select message requests and then finally filtered requests. Now all of the messages you received will be listed here in chronological order. Now people can have important messages here that they couldn’t see before.
These messages were filtered due to the fact that people spam other accounts a lot and the inbox was always full of these messages in the early days. However, there are no notifications available that address this issue of relegating messages to the other section. Facebook does that on its own and very efficiently at that. Facebook can sense that you might know the reader like if you have some mutual friends it will give a notification but if you are completely disconnected, it will send them to this folder. Also, there is the money matter as well.
Facebook in an unusual move allowed people to send other users they didn’t know a message by charging $1 per message. Now this message would certainly be delivered to the person in the inbox and not the message requests folder. So, ultimately money making trumps all I guess. This was all a plot to make money!