Is it possible to let Exim do not resolve IP to host? Like not it tries to:

2004-08-04 17:16:23 1BsT7S-0003n9-Fs <= xxx@xxx.com H=(xxx.xxx.uk) [4.xxx.124.xx] P=smtp S=19948 id=NNCLAIMFMNPPLMMLAFANMFLKPDAA.xxx@xxx.uk

Any ideas are welcome.