Here is a list of issues that were fixed in this release - build 2.6.23.

Issue Key Description
AVSUPPORT-35143, AVSUPPORT-33703 For some customers the automated Custom Query quarantine action did not perform the quarantine operation on emails. A fix was applied to the actions of automated queries mechanism.
AVSUPPORT-30195, AVSUPPORT-28198, AVSUPPORT-28542 For a specific customer all emails from external were being delivered twice. The issue occurred when using Check Point Threat Extraction security tool.