Hi chen,
This can be done in the .htm page by commenting the code which is responsible for this block.
Open component 'CRMCMP_CCS_EML’ . Now go to the ViewSet 'CRMCMP_CCS_EML/MailRightViewSet ' in the runtime repository you will find the view area named as 'MailInteractionArea '.
Image may be NSFW.
Clik here to view.
Image may be NSFW.
Clik here to view.
And now if you will see in the .htm page of view set 'MailRightViewSet.htm' there is a code
Image may be NSFW.
Clik here to view.
This is responsible for the Current Interaction record assignment block. Comment out the code highlighted above .
Thanks
Kumar.