HDP version 5.2.12 (revision 18620) is available for customers from April 2016. 

Here's the release notes:

1. JIRA related bug fixes
2. Fixed bug where timestamp on updates was showing incorrectly
3. Fixed bug where deactivated staff was shown on the reports forms
4. Fixed bug where if multi branding is not enabled KB article page and/or support center gave an error
5. Fixed bug where deferred action for a scheduled report continued to execute even after the scheduled report is deleted/disabled
6. Fixed bugs where CC recipients list was not sanitised (in which case ticket detail page would break)
7. LDAP Integration related fixes
8. Fixed bug - cascading delete of tickets when client associated to last_client_message is deleted
9. Fixed bug - name of contact is updated on loser tickets to that of the winner ticket, when contact merge is done

1. Changed count of errors allowed per day for IMAP/POP polling before which mail execution will be stopped. Changed the count from 10 to 1000 per day.
2. Russian language translation enhancements
3. Full access to to account admin for scheduled reports and reports
4. Webhooks are now supported in HDP
5. Added MAXLINE in poplib to handle longer lines - to be able to download larger emails from POP mailboxes