anchor.diff:        // Alternative or mixed?
         var multipartType = html != null && text != null ? 'alternative' : 'mixed';
   
  -      buffer.write('Content-Type: multipart/$multipartType; boundary="$boundary"\r\n');
  +      buffer.write('Content-Type: multipart/$multipartType; boundary="$boundary"\n\n');
   
         // Insert text message.
         if (text != null) {
  -        buffer.write('--$boundary\r\n');
  -        buffer.write('Content-Type: text/plain; charset="${encoding.name}"\r\n');
  -        buffer.write('Content-Transfer-Encoding: 7bit\r\n\r\n');
  -        buffer.write('$text\r\n\r\n');
  +        buffer.write('--$boundary\n');
  +        buffer.write('Content-Type: text/plain; charset="${encoding.name}"\n');
  +        buffer.write('Content-Transfer-Encoding: 7bit\n\n');
  +        buffer.write('$text\n\n');
         }
   
         // Insert HTML message.
         if (html != null) {
  -        buffer.write('--$boundary\r\n');
  -        buffer.write('Content-Type: text/html; charset="${encoding.name}"\r\n');
  -        buffer.write('Content-Transfer-Encoding: 7bit\r\n\r\n');
  -        buffer.write('$html\r\n\r\n');
  +        buffer.write('--$boundary\n');
  +        buffer.write('Content-Type: text/html; charset="${encoding.name}"\n');
  +        buffer.write('Content-Transfer-Encoding: 7bit\n\n');
  +        buffer.write('$html\n\n');
         }
   
         // Add all attachments.
  
positive.code:           fromData = '$fromName <$fromData>';
          }
  
          buffer.write('From: $fromData\r\n');
        }
  
        if (recipients != null && recipients.length > 0) {
          var to = recipients.map((recipient) => _sanitizeEmail(recipient)).toList().join(',');
          buffer.write('To: $to\r\n');
        }
  
        buffer.write('X-Mailer: Dart Mailer library\r\n');
        buffer.write('Mime-Version: 1.0\r\n');
  
        // Create boundary string.
        var boundary = '$identityString-?=_${++_counter}-${new DateTime.now().millisecondsSinceEpoch}';
  
negative.code:           // Create a chunk'd (76 chars per line) base64 string.
            var contents = CryptoUtils.bytesToBase64(bytes, addLineSeparator:true);
  
            buffer.write('--$boundary\n');
            buffer.write('Content-Type: ${getContentType(filename: attachment.file.path)}; name="$filename"\n');
            buffer.write('Content-Transfer-Encoding: base64\n');
            buffer.write('Content-Disposition: attachment; filename="$filename"\n\n');
            buffer.write('$contents\n\n');
          });
        }).then((_) {
          buffer.write('--$boundary--\n\n.');
  
          return buffer.toString();
        });
      });
    }
  }
  