Actually I emailed 2 other valid users on that domain, all with the same result, so I don't think the problem is user-specific. I'm suspecting the problem to be the reverse DNS lookup too. As I said before I'm having problem with some other European domains as well. With this one, I don't get the bounce back, but he never even receives the email, although again if I send it from Yahoo, he'll get it fine and reply back.
Here's the SMTP log on that: +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ A connection to 194.109.6.48 was established. 2/5/03 1:51:11 PM : <<< 220 mxzilla4.xs4all.nl ESMTP Sendmail 8.12.3/8.12.3; Wed, 5 Feb 2003 19:56:41 +0100 (CET) 2/5/03 1:51:11 PM : >>> EHLO s-mail.visionics.com 2/5/03 1:51:11 PM : <<< 250-mxzilla4.xs4all.nl Hello [63.122.164.131], pleased to meet you 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-8BITMIME 250-SIZE 15000000 250-DSN 250-ETRN 250-DELIVERBY 250 HELP 2/5/03 1:51:11 PM : >>> MAIL FROM:<[EMAIL PROTECTED]> SIZE=4229 RET=FULL 2/5/03 1:51:11 PM : <<< 250 2.1.0 <[EMAIL PROTECTED]>... Sender ok 2/5/03 1:51:11 PM : >>> RCPT TO:<[EMAIL PROTECTED]> NOTIFY=FAILURE,DELAY 2/5/03 1:51:12 PM : <<< 250 2.1.5 <[EMAIL PROTECTED]>... Recipient ok 2/5/03 1:51:12 PM : >>> DATA 2/5/03 1:51:12 PM : <<< 354 Enter mail, end with "." on a line by itself 2/5/03 1:51:12 PM : <<< 250 2.0.0 h15IufMR063553 Message accepted for delivery 2/5/03 1:51:12 PM : >>> QUIT 2/5/03 1:51:12 PM : <<< 221 2.0.0 mxzilla4.xs4all.nl closing connection ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Is there anything I can do on my end to get rid of the reverse DNS problem? Thanks --Alex Alborzfard Network Errand Boy MCSE, CCNA, CCDA, CCISP -----Original Message----- From: Ed Crowley [mailto:[EMAIL PROTECTED]] Sent: Wednesday, February 05, 2003 2:10 PM To: Exchange Discussions Subject: RE: Mysterious bounced message I wandered off in the wrong direction, sorry. I just tried pretty much the same thing your server tried and the recipient is ok. >From the transcript you provided, either: - The recipient wasn't there when the mail was originally sent, - The server was momentarily screwed up, - It's doing some kind of reverse DNS lookup test that your sending server doesn't pass and it's giving you the wrong error message, or - Something else I haven't thought of. I don't think the problem is on your end. 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 10:47 AM To: Exchange Discussions Subject: RE: Mysterious bounced message Not that I'm aware of. How would I find out for sure? I know that we're connected to Internet via a Frame Relay to our HQ, so our incoming and outgoing traffic has to go through the HQ network and their firewall. I also know that they added a 2nd line, which has a different public IP address. But that was not supposed to affect us, because we're still hanging off the old line (and router). Also our mail server's public IP address never changed and we are able to send/receive email as before. --Alex Alborzfard Network Errand Boy MCSE, CCNA, CCDA, CCISP -----Original Message----- From: Ed Crowley [mailto:[EMAIL PROTECTED]] Sent: Wednesday, February 05, 2003 1:12 PM To: Exchange Discussions Subject: RE: Mysterious bounced message 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] _________________________________________________________________ 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] _________________________________________________________________ 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]
