Previously, we were indexing e-mails and its attachments together. We changed this logic with
CONNECTORS-1375 as indexing e-mail and its attachments separately.
However, there is a problem. Content fields of emails which has attachment(s) includes both body and attachments's binary content as plain text.
As we index attachments separately, we can just index body as content instead of appending email body and all attachments' binary data as plain text.