"Diagnostic-Code: smtp; 500 Syntax error, command unrecognized" sounds a lot like what a previous poster was talking about (SMTP Problems thread from Matt Plahtinsky). It seems that some bad NIC drivers cause problems for exchange servers when sending SMTP to other exchange servers (and maybe other MTA's, though I've only seen this with exchange to exchange communications). I thought they had a KB article about it but I can't find it now and google is being just as stingy. Have that other company update their NIC drivers (and update yours).
On Fri, 14 Jan 2005 08:29:53 -0500, Alex Alborzfard <[EMAIL PROTECTED]> wrote: > Thanks, I'll ask them to do that. We have the latest Symantec running on the > EX box, which has some anti-spam capabilities. > If Symantec is blocking it, it should be at least logging it as well. I'll > check the logs to see if there's a delivery attempt. > > Alex Alborzfard > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Andy > David > Sent: Thursday, January 13, 2005 7:54 PM > To: Exchange Discussions > Subject: RE: SMTP Error 500 > > Have them telnet from their mail server to yours on port 25 and attempt to > send a test message. > Any anti-spam products installed on your mailserver or gateways? > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Alex > Alborzfard > Sent: Thursday, January 13, 2005 4:37 PM > To: Exchange Discussions > Subject: SMTP Error 500 > > A customer can receive from, but cannot send email to our domain. > He gets a bounce back with the error: > "Diagnostic-Code: smtp; 500 Syntax error, command unrecognized" > at the end of the message. > > There is no trace of this in the SMTP logs or Message Tracking. Couldn't > find anything useful Googling. What could be causing this? > > Alex Alborzfard [snip] _________________________________________________________________ List posting FAQ: http://www.swinc.com/resource/exch_faq.htm Web Interface: http://intm-dl.sparklist.com/read/?forum=exchange To subscribe: http://e-newsletters.internet.com/discussionlists.html/ To unsubscribe send a blank email to [EMAIL PROTECTED] Exchange List admin: [EMAIL PROTECTED] To unsubscribe via postal mail, please contact us at: Jupitermedia Corp. Attn: Discussion List Management 475 Park Avenue South New York, NY 10016 Please include the email address which you have been contacted with.
