my e-mail was rejected

I sent a proposal to proposals@oreilly.com, and got a message saying my e-mail was rejected as spam;

The original message was received at Tue, 6 May 2008 17:59:11 -0400
from 75-93-0-128.eug.clearwire-dns.net [75.93.0.128]

----- The following addresses had permanent fatal errors -----
<proposals@oreilly.com>
(reason: 550-Host 69.49.106.15 is blocked: 550 Mail refused from spam source)

----- Transcript of session follows -----
... while talking to smtp1.oreilly.com.:
>>> DATA
<<< 550-Host 69.49.106.15 is blocked: 550 Mail refused from spam source
<<< 550 (InternetNamesForBusiness.com) by local blocking list
550 5.1.1 <proposals@oreilly.com>... User unknown
451 4.4.1 reply: read error from smtp1.oreilly.com.
 
sad I’m frustrated
Inappropriate?
2 people have this problem
User_gray