Do you have a host between the Internet and the internal network that is readdressing mail?
Ed Crowley MCSE+Internet MVP kcCC+I Tech Consultant hp Services Protecting the world from PSTs and Bricked Backups! -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Alex Alborzfard Sent: Wednesday, February 05, 2003 9:17 AM To: Exchange Discussions Subject: Mysterious bounced message EX 5.5 SP4 on NT SP6a Messages sent to users at certain domain in Europe (Italy) from our Exchange mailbox bounce back undelivered as "User unknown": However when they are sent from a Yahoo account, they get delivered without a problem. I verified connectivity to recipient's mail server by pinging and telnetting to port 25 successfully. I even specified the recipient's mail server IP address instead of relying on DNS, but the problem still persisted. I turned on the SMTP Protocol Logging on IMC. Here's the result: ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2/5/03 11:49:31 AM : A connection to 195.120.145.5 was established. 2/5/03 11:49:31 AM : <<< 220 addon.it ESMTP MDaemon 6.0.3; Wed, 05 Feb 2003 17:47:16 +0100 2/5/03 11:49:31 AM : >>> EHLO s-mail.visionics.com 2/5/03 11:49:32 AM : <<< 250-addon.it Hello s-mail.visionics.com, pleased to meet you 2/5/03 11:49:32 AM : <<< 250-ETRN 250-AUTH LOGIN CRAM-MD5 250-8BITMIME 250 SIZE 0 2/5/03 11:49:32 AM : >>> MAIL FROM:<[EMAIL PROTECTED]> SIZE=3830 2/5/03 11:49:32 AM : <<< 250 <[EMAIL PROTECTED]>, Sender ok 2/5/03 11:49:32 AM : >>> RCPT TO:<[EMAIL PROTECTED]> 2/5/03 11:49:33 AM : <<< 550 <[EMAIL PROTECTED]>, Recipient unknown 2/5/03 11:49:33 AM : >>> QUIT +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Also we have been having similar problems with other european recipients. Any ideas what could be causing this? Thanks --Alex Alborzfard Network Errand Boy MCSE, CCNA, CCDA, CCISP _________________________________________________________________ List posting FAQ: http://www.swinc.com/resource/exch_faq.htm Archives: http://www.swynk.com/sitesearch/search.asp To unsubscribe: mailto:[EMAIL PROTECTED] Exchange List admin: [EMAIL PROTECTED] _________________________________________________________________ List posting FAQ: http://www.swinc.com/resource/exch_faq.htm Archives: http://www.swynk.com/sitesearch/search.asp To unsubscribe: mailto:[EMAIL PROTECTED] Exchange List admin: [EMAIL PROTECTED]
