Automated @replies and mentions
The @reply and Mention functions are intended to make communication between users easier, and automating these processes in order to reach many users is considered an abuse of the feature. If you are automatically sending @reply messages or Mentions to many users, the recipients must request or approve this action in advance. For example, sending automated @replies based on keyword searches is not permitted.
Users should also have an easy way to opt-out of your service (in addition to the requirement that all users must opt-in before receiving the messages). We review blocks and reports of spam, so you’ll need to provide a clear way for users to opt-out from your messages.