Notification Assistant for Jira Cloud will show you emails sent by the app on a given Jira site, or a single Jira issue. Email activity will be retained for 30 days.
Please be aware that emails may take up to 20 minutes to show up after being sent
Single Issue
You can click the Email Activity Log button in the Activity section of your Issue to see past emails and their status. This requires Project or Jira Administrator permissions.
Jira Site
A Jira site administrator can see all email activity logs across the entire system by going to
https://<YOUR SITE>.atlassian.net/plugins/servlet/ac/com.riadalabs.jira.plugins.notificationassistant/app-nafj-jira-admin-activity?s=com.riadalabs.jira.plugins.notificationassistant__app-nafj-jira-admin-activity
Or you can go to the Apps section of the admin UI, and then pick Activity Log in the Notification Assistant for Jira section: