Hi,
Try the attachment.
l_subject = subject.
CREATE OBJECT l_document.
l_document = cl_document_bcs=>create_document(
i_type = 'HTM'
i_subject = l_subject
i_length = '1000'
i_language = sy-langu
i_importance = '1'
i_text = document_content delete this
i_hex = it_solix_tab delete this
).
IMHO you can use plain text or html in the body of the message.
See here Multi Line Cell In Excel Using CSV by Mail
a sample of a mail body .
Regards .