The original message was received at Tue, 19 Aug 2003 18:51:14 -0700 (PDT) from pcp802046pcs.nrockv01.md.comcast.net [68.48.85.148] ----- The following addresses had permanent fatal errors ----- &lt;3Dcstohs(a)cisco.com&gt; (reason: 550 5.1.1 &lt;3dcstohs(a)sj-core.cisco.com&gt;om>... User unknown) (expanded from: &lt;3Dcstohs(a)cisco.com&gt;) ----- Transcript of session follows ----- ... while talking to sj-core-3.cisco.com.: <<< 550 5.1.1 &lt;3dcstohs(a)sj-core.cisco.com&gt;om>... User unknown 550 5.1.1 &lt;3Dcstohs(a)cisco.com&gt;om>... User unknown <<< 503 5.0.0 Need RCPT (recipient)