Hi Anjum,
You can try to read the current business transaction GUID in email view by reading global data context reference. Something like this:
*- Data dictionary
DATA lr_gdc TYPE REF TO if_crm_ui_data_context.
DATA lr_bt TYPE REF TO cl_crm_bol_entity.
DATA lv_guid TYPE crmt_object_guid.
*- Get current business transaction from global data context
lr_gdc ?= cl_crm_ui_data_context_srv=>get_instance( ).
CHECK lr_gdc IS BOUND.
lr_bt ?= lr_gdc->get_entity( name = if_iccmp_global_data_cont_con=>gdc_currentbt ).
CHECK lr_bt IS BOUND.
lv_guid = lr_bt->get_property_as_string( 'CRM_GUID' ).
Kind regards,
Garcia