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.
...
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
...
Or you can go to the Apps section of the admin UI, and then pick Activity Log in the Notification Assistant for Jira section:
...
...
Enable Tracing
From the site wide Activity Log UI, you can click on the cog icon in the upper right and then enable tracing which will show a higher level of logging:
...