How to exclude users who have opted out, from campaigns?

You might often want to exclude users who have opted out from all your campaigns. Doing this is simple:

• First ensure that your opt-in data is up to date. This can be regularly updated through conversational data, by uploading fresh data through CSV, or by using REST APIs to sync with your CRM.
• Next, you can include a condition in your segment where, “Opt-in is true”. This segment will exclude all users for whom the opt-in is either false or unknown.