After sending messages in Joinable, the message sender is able to see who has opened, read and responded to their messages, as well as view how the message were delivered (in app, email, by text message or in a digest).
The sender can optionally "nudge" members who have not viewed the message—this sends a reminder message to only the selected members. The Engagement Insights icon is located in the opened message view at the top of the page (looks like a page with an arrow).
The Engagement Insights feature respects anti-snooping features, such as Apple's Mail Privacy Protection. As such, the reliability of email engagement data is unknown, and variability should be taken into account. A sender is able to see which members received emails and should use good judgment before assuming the message was not read or received.
This feature is only available to the sender of each message, but can also be seen by the group admins for the purpose of assisting and troubleshooting member engagement issues. It intentionally offers limited visibility into the actions of each group member to respect privacy, which we respect. Read our Privacy Promise.