这是插值的问题，我将使用以下方法解决此问题：

# open and read archive to send in attachment
file = File.open(path_from_csv_created).read

resp = ses_client.send_raw_email(
      source: 'email_send',
      destinations: ['email_to_receive'],
      raw_message: {
        data: <<~MESSAGE
          From: email_send
          To: email_to_receive
          Subject: Test email (contains an attachment)
          MIME-Version: 1.0
          Content-type: Multipart/Mixed; boundary="NextPart"

          --NextPart
          Content-Type: text/plain

          bodyyyy

          --NextPart
          Content-Type: application/csv;
          Content-Disposition: attachment; filename="#{file_csv_name}"

          #{file}
        MESSAGE
      }
    )