select cr.content as plain_text
from acs_mail_multipart_parts mpp
join cr_items ci on mpp.content_item_id=ci.item_id
join cr_revisions cr on ci.live_revision=cr.revision_id
where multipart_id=:content_item_id and cr.mime_type='text/plain';
select cr.content as html_text
from acs_mail_multipart_parts mpp
join cr_items ci on mpp.content_item_id=ci.item_id
join cr_revisions cr on ci.live_revision=cr.revision_id
where multipart_id=:content_item_id and cr.mime_type='text/html';