How are messaging platforms tackling spam?

Messaging apps are certainly aware that spam could be a big problem when it comes to chat bots and they're taking measures to ensure that end-users are not affected by spammy bots. For instance, bots on Facebook Messenger cannot  initiate contact with a user until the user makes the first interaction. Also if more than 4% of your users block your bot, they will temporarily suspend the bot account. Each messaging app has their own way to tackle spam so do be mindful of this while building your bot.