Zip file/attachment cl_abap_zip

 *Use cl_abap_zip to zip file(s) for download or email    
  DATA: g_zip TYPE REF TO cl_abap_zip.    
     
  CREATE OBJECT g_zip.    
     
  CONCATENATE 'File1' '.xls' INTO im_type.    
     
  CALL METHOD g_zip->add    
   EXPORTING    
   name = im_type    
   content = l_xstring.    
     
  CALL METHOD g_zip->save    
  RECEIVING    
  zip = gs_zip.