HI @giuliap42357798  You may reference to the below:   https://experienceleague.adobe.com/docs/campaign-standard/using/communication-channels/transactional-messaging/transactional-messaging-limitations.html?lang=en   https://experienceleaguecommunities.adobe.com/t5/adobe-campaign-standard/maximum-si...

HI @John_Man    There was an older thread that has referred to below. Visitor Tracking Between an App and Mobile Web     In terms of the web implementation you can either use the default implementation by implementing the AppMeasurement.js and VisitorAPi.js or use a Tag management System (DTM or Lau...