Notifications are not being sent to customers mentioned in internal comments in Jira Service Management Data Center
Platform Notice: Data Center - This article applies to Atlassian products on the Data Center platform.
Note that this knowledge base article was created for the Data Center version of the product. Data Center knowledge base articles for non-Data Center-specific features may also work for Server versions of the product, however they have not been tested. Support for Server* products ended on February 15th 2024. If you are running a Server product, you can visit the Atlassian Server end of support announcement to review your migration options.
*Except Fisheye and Crucible
Summary
Email notifications are not being sent to customers mentioned in internal comments in Jira Service Management projects.
Environment
Jira Service Management 4.20.0+.
Cause
For customers there is no concept of "mention" notification - this is a type of notification reserved for agents (users with a license). Instead, when customers (reporters, participants, approvers, members of organization the request is shared with) are mentioned in a public comment, they can receive the "Public comment" type of customer notification. If the comment is internal, then no notification will be sent to the users treated as customers. This is the expected behavior.
Solution
This behavior is as expected. To ensure that customers receive a notification, they must be mentioned in public comments.