Why can WeChat send messages without being a friend?

The reason why WeChat can send messages without friends may be: 1. We used to be friends, but then one party deleted the other party, and the other party didn't know, so the other party could still send messages. 2. Once in a common group chat, even if you are not friends, you can send messages in the group chat. 3. The other party may add you as a friend by searching your micro signal or mobile phone number. In this case, you are not friends, but the other party can send you messages in this way.