Пример без вложения.
Если у Вас он не отрабатывает, обратитесь к базису, пусть они сделают необходимые настройки в системе
DATA:
lt_header LIKE TABLE OF solisti1,
ls_document_data LIKE sodocchgi1,
lt_content TYPE TABLE OF solisti1,
lt_receivers TYPE TABLE OF somlreci1,
ls_receivers LIKE LINE OF lt_receivers,
ls_content LIKE LINE OF lt_content.
* получатель
ls_receivers-receiver =
'user@domain.com'.
ls_receivers-rec_type = 'U'.
APPEND ls_receivers TO lt_receivers.
* Заголовок
ls_document_data-obj_langu = sy-langu.
ls_document_data-obj_descr = 'Заголовок письма'.
* Тело письма
ls_content = 'Привет, Мир!'.
APPEND ls_content TO lt_content.
ls_content = 'С уважением.'.
APPEND ls_content TO lt_content.
* Отправка
CALL FUNCTION 'SO_NEW_DOCUMENT_SEND_API1'
EXPORTING
document_data = ls_document_data
put_in_outbox = 'X'
commit_work = 'X'
TABLES
object_header = lt_header
object_content = lt_content
receivers = lt_receivers
EXCEPTIONS
too_many_receivers = 1
document_not_sent = 2
document_type_not_exist = 3
operation_no_authorization = 4
parameter_error = 5
x_error = 6
enqueue_error = 7
OTHERS = 8.