[exim] Disable dns_check_names_pattern

Hello everyone. We migrate our infrastructure postfix to exim. However,
an old application (mail to fax) uses a domain "[ip-address]". This
illegal domain works with postfix and not with exim. I try to disable
"dns_check_names_pattern" but my mail is rejected.

---
sendmail -bP
.
.
.

deliver_queue_load_max =
delivery_date_remove
no_disable_ipv6
dkim_verify_signers = $dkim_signers
dns_again_means_nonexist =
dns_check_names_pattern =
.
.
.
---

My test :
---
echo "" | mutt -a "/tmp/test.pdf" -- infos@???
Error sending message, child exited 1 ().
Could not send the message.
---

Do you have any idea?

Thank you
Alex.