Facebook’s ‘Other’ inbox is basically the island of misfit messages, a ghost town you rarely check, filled with mostly garbage. You don’t get notifications for it, and if you never click into the folder then everything in there will go unnoticed forever.
But while many of us might give it a passing glance and move on, you should know that there are only five types of messages in everyone’s ‘Other’ inbox – and here they are.
Confused friends who don’t know how to add you
If you’re not friends with someone and you try to send them a message, it will get automatically sorted into the “Other” folder, potentially never to be seen again. So if you want to reach out to an old buddy and you’re thinking about messaging them before you take the plunge and send a friend request, just send the friend request. 
You’ll usually get messages from people you actually know sent to the “Other” photo when they’re an older Facebook user who isn’t fully clear on how to add you. This is probably the reason you want to check your folder, just to make sure you’re not missing out on any digital friendship. A girl I met traveling sent me a message but for whatever reason didn’t also send a friend request, so I looked like a jerk since it took me months to go through my ‘Other’ box and find it. Whoops.
Event updates
One of the only good things about the invention of the ‘Other’ category is its ability to siphon out some of the messages from events that used to crowd our inboxes. If you RSVP for an event, sometimes the planners take that as a sign that you won’t mind reading 14 updates leading up to said event. Most of these messages don’t say anything of value, but occasionally they’ll announce something important like a venue change, and then you’ll be cursing Facebook for creating a folder seemingly designed to make you four hours late to a surprise birthday party.
Page Updates
If you follow a local band or you ‘liked’ your favorite neighborhood restaurant, updates they send out will often end up in the ‘Other’ folder… which is fine by me. Sure, you might miss a notice for a sale, but did you really want a notice for a sale?
Creepers
Perhaps the most common sight in your ‘Other’ inbox, depending on your gender: weird messages from people of the opposite sex who haven’t grasped that Facebook isn’t a long-distance dating service. While generally not malicious, these messages can get annoying because the people sending them tend to make them extremely generic (“I like your picture”) and the chances that they’re just mass messaging every person they deem attractive are… extremely high. This is how catfishing starts, folks.
Spam
