Hello Rakesh,
Instead of navigating to the E-Mail Editor to display the E-Mail content, the customer should implement the preview button of the Agent Inbox. This allows to display the E-Mail directly in agent inbox without further navigation.
This button can be added to the agent inbox toolbar with business function IC Inbox Extensions (CRM_IC_INBOX) according to SAP Help for CRM 7.0 EHP3 .
See also KBA 2066571 for screenshots.
Best Regards,
Sigrid