Raley automatically assigns "References" header to all emails which are sent by specific notification configuration for specific Jira issue. This enables grouping of emails as in example below:
In other words, if Notification configuration A sends an email notification about Jira ticket X, then the resulting email will contain a References header that will contain Message-ID's of all emails previously sent by notification configuration A for issue X.
This applies to all emails send in the last 30 days.
