If you're getting this message:
Some of your messages have been reported as spam. To avoid getting blocked, make sure your messages are in line with the Facebook Community Standards.
The block will be active for 23 days and 3 hours more.
Then you've already been blocked by Facebook for one of many possible reasonS. The most common reason people get blocked is for inviting friends too frequently.
To be safe, you should only invite 15 people a day max. When you invite friends who aren't ' riends of friends' Facebook, will ask the person you've inviting if they know you or not. If too many people select the option that they don't know you too many times, Facebook blocks you.
Promoting Facebook profiles
If you have a Facebook profile, mainly for promoting your Facebook page, invite the friends who have the most friends in common with you to decrease your chances of getting blocked again.
