Dear Helmut,
As per my knowledge, Its not possible to add body in mail when u r using mension smart form and class.
But you can do this by method call action.
Please refere below sample code to send mail in HTML format.
lv_send_request TYPE REF TO cl_bcs,
lv_document TYPE REF TO cl_document_bcs,
lt_sender TYPE REF TO cl_sapuser_bcs,
*-- Create persistent send request
lv_send_request = cl_bcs=>create_persistent( ).
lv_sub = lv_subj.
*-- Create Document
lv_document = cl_document_bcs=>create_document(
i_type = cv_htm
i_text = lt_contents1
i_length = lv_doc_len
i_subject = lv_sub
i_language = sy-langu
i_importance = '5' ).
CALL METHOD lv_document->add_attachment
EXPORTING
i_attachment_type = 'jpg'
i_attachment_subject = 'logo'
* i_attachment_size = lv_img1_size
i_att_content_hex = lt_hex1.
TRY.
*-- Set the Message Subject
CALL METHOD lv_send_request->set_message_subject
EXPORTING
ip_subject = lv_subj.
CATCH cx_sy_dyn_call_illegal_method. "#EC NO_HANDLER
ENDTRY.
*-- Add document to send request
CALL METHOD lv_send_request->set_document( lv_document ).
*-- Do send delivery info for successful mails
CALL METHOD lv_send_request->set_status_attributes
EXPORTING
i_requested_status = 'E'
i_status_mail = 'A'.
*-- Set sender
lt_sender = cl_sapuser_bcs=>create( sy-uname ).
CALL METHOD lv_send_request->set_sender
EXPORTING
i_sender = lt_sender.
**-- Add the recipients to the Send mail
CLEAR : lv_rcv_email,lv_partner.
REFRESH : lt_bapiadsmtp,lt_return.
IF lv_recipient1 IS NOT INITIAL.
lv_partner = lv_recipient1.
CALL FUNCTION 'BAPI_BUPA_ADDRESS_GETDETAIL'
EXPORTING
businesspartner = lv_partner
TABLES
bapiadsmtp = lt_bapiadsmtp
return = lt_return.
READ TABLE lt_bapiadsmtp INTO ls_bapiadsmtp INDEX 1.
IF sy-subrc EQ 0.
lv_rcv_email = ls_bapiadsmtp-e_mail.
ENDIF.
ENDIF.
CHECK NOT lv_rcv_email IS INITIAL.
lt_recipient = cl_cam_address_bcs=>create_internet_address(
lv_rcv_email ).
CALL METHOD lv_send_request->add_recipient
EXPORTING
i_recipient = lt_recipient
i_express = abap_true.
lv_send_request->set_send_immediately( 'X' ).
*-- Send Email
CALL METHOD lv_send_request->send(
EXPORTING
i_with_error_screen = abap_true
RECEIVING result = lv_result ).
Thanks,
Vikas