- users from Jira
- email addresses
- Persons related to the issue or project: Assignee, Reporter, Watchers, Project Lead, Current User
- Project Roles
- User Groups
- Custom Fields that may hold email addresses or users or groups
The available user groups, project roles and custom fields may be limited in the Recipient Restrictions. This is useful for example if you want to avoid users accidentally selecting "jira-users" group as a recipient and hence to send emails to all users.