WeChat doesn’t have any opt-in requirements as it is not possible to send messages to WeChat users unless they follow your Official Account. When a WeChat user starts to follow your Official Account, you can reply to 3 messages within a minute.
You are not permitted to send more than 3 messages a minute, unless followers:
- Initiate a chat with your Official Account, then you can reply 20 messages within 48 hours with every reply.
- or they click on the custom chat menu on the bottom, then you can reply 3 messages within a minute.