I'm guessing that the .nl node can't handle source routing. Or is there some other problem that someone can identify. - - The original note follows - - SAMPLE OF RETURNED MAIL Date: Tue, 21 Sep 93 06:01:12 -2300 From: [log in to unmask] Subject: Returned mail: Remote protocol error To: ... Status: OR ----- Transcript of session follows ----- >>> MAIL From:<@estec.esa.nl:@PSUVM.PSU.EDU:[log in to unmask]> <<< 501 Syntax Error. Invalid Local Part of Address 554 pingmann@estec... Remote protocol error: Bad file number ----- Unsent message follows ----- Received: from psuvm.psu.edu by bcserver.estec.esa.nl (AIX 3.1/UCB 5.61/4.03) id AA11278; Tue, 21 Sep 93 23:07:35 -2300 Message-Id: <[log in to unmask]> Received: from PSUVM.PSU.EDU by PSUVM.PSU.EDU (IBM VM SMTP V2R2) with BSMTP id 2747; Tue, 21 Sep 93 17:08:14 EDT Received: from PSUVM.PSU.EDU (NJE origin LISTSERV@PSUVM) by PSUVM.PSU.EDU (LMail V1.1d/1.7f) with BSMTP id 6466; Tue, 21 Sep 1993 14:28:51 -0400 Date: Tue, 21 Sep 1993 14:26:47 EDT Sender: CLIMLIST Climatology Distribution List <[log in to unmask]> From: John Arnfield <[log in to unmask]> Subject: Position available (USA) X-To: CLIMLIST <[log in to unmask]> To: Multiple recipients of list CLIMLIST <[log in to unmask]> ...