cbl.abuseat.org listing

OSX 10.4.8 server's IP address is continually getting listed by cbl.abuseat.org. the reason given is: [i]Note: 209.242.15.90 was found to be using the following name during connections: localhost Which is an illegal name according to the RFC2821 SMTP mail protocol standards. RFC2821 requires that the machines claim names that are a fully qualified domain names or IP addresses enclosed in square brackets.[/i] i think the offending mail header is this one:[i] Received: from localhost.localdomain (209.242.15.90) by mail.evdoinfo.com[/i] can someone tell me where to look to change 'localhost.localdomain' ? FYI, email is being sent via php app called supporttrio, via SMTP server which is EIMS-X.