I am running sendmail 8.9.3-23. I host several small web sites. One of my clients is sending mail and the receiving server denies it because it says "Relaying Denied," I assume because my client is coming from my mail server (tully.dailydatainc.com) but has their return address (brion-enterprises.com) in the "From" field. I am using one IP address for everyone. Any ideas? I can send the headers if necessary. Thanks, Rod