The Encrypt Button is showing ( connect to right management servers and get template using outlook

The Encrypt Button is showing ( connect to right management servers and get template using outlook 2016 version 2402 Monthly enterprise channel

The Encrypt Button is showing ( connect to right management servers and get template using outlook 2016 version 2402 Monthly enterprise channel

However the same option is working in new outlook client and OWA

the IRM configuration is checked and the Option is enabled and tested the IRM configuration - Overall result is pass

Could you please check and let me know what might be the issue in Classic outlook ?

Every thing is working in new Outlook and OWA with out any issue. Please check the screenshot from the classic outlook

the encrypt button was not available in classic outlook have checked and changed the registry settings .