It appears to me that chudys.com is totally clueless. Their response to your inquiry is meaningless techno-babble, their mail server is a confirmed open relay (see below), and their rejection of messages with null return-path addresses is in violation of Internet mail standards (see RFC 821 and RFC 1123). You did not provide the headers for the rejected message, but the text of the 550 error message and the null return address on the rejected message lead me to believe that the return-path address was also null. -- Paul Russell Senior Systems Administrator University of Notre Dame ----- Begin forwarded message ----- >Received: from mail.chudys.com (mail.chudys.com [216.228.97.2]) by > dagger.nd.edu (8.10.2/8.10.2) with ESMTP id e9JGOb129235 for > <[log in to unmask]>; Thu, 19 Oct 2000 11:24:41 -0500 (EST) >Received: from sunbear.cc.nd.edu (sunbear.cc.nd.edu [129.74.36.107]) by > mail.chudys.com (Postfix) with SMTP id 295B4113005 for > <[log in to unmask]>; Thu, 19 Oct 2000 12:23:35 -0400 (EDT) >Date: 19 Oct 2000 11:23:52 -0500 >Subject: relay test of mail.chudys.com >To: <[log in to unmask]> >From: <[log in to unmask]> >Message-ID: <[log in to unmask]> > >This is a test. ----- End forwarded message -----