[Exim] use IP on SMTP HELO instead of foo.bar

Helo, some hosts give my 504 after HELO if i don't use mi IP in
numeric format, who can i tell exim to use "numeric IP" in his SMTP
sessions?

-- 
Alberto Cortés Martín     | Ing. de Telecomunicaciones
email: alcortes@???  | Universidad Carlos III
tel: +34 91 450 09 85     | Madrid
cel: 600 42 77 57         | Spain
icq# 101088159            |