[exim] despammed.com

Has anybody delivery problems to despammed.com?

   postmaster@???
     SMTP error from remote mail server after RCPT  
TO:<postmaster@???>:
     host mail.despammed.com [65.112.71.26]: 550 5.7.1  
<postmaster@???>... Relaying denied. IP name lookup failed  
[81.174.30.132]

I do not understand the reason, my DNS is fine and I tried three
times from three different domains.

Any ideas? (apart from blacklisting them, for good measure)

Thanks

Giuliano