i had a user contact me saying he cant send email to some of his clients today. i tried telnetting to there mail server and i can get connected, but when i type in the clients email address and hit enter i get. see output below: 220 WIN-F57QL28JQC8.maryem.info Microsoft ESMTP MAIL Service ready at Thu, 9 Dec 2010 19:26:04 -0800 helo mydomain.com 250 WIN-F57QL28JQC8.maryem.info Hello [my external email ip address] mail from:administrator@mydomain.com 250 2.1.0 Sender OK rcpt to:client@theexternaldomain.org 550 5.7.1 Unable to relay the way i am understanding the telnet output is that the problem is on the external domain side? can anyone assist me with this? if it is a problem on my end what is the best way to start troubleshooting this? here is the NDR my user received: Diagnostic information for administrators: Generating server: exchangeserver01.mydomain.com ashgan.osman@clientsexternaldomain.org WIN-F57QL28JQC8.maryem.info #550 5.7.1 Unable to relay ## aziz@clientsexternaldomain.org WIN-F57QL28JQC8.maryem.info #550 5.7.1 Unable to relay ## sherif.elabd@clientsexternaldomain.org WIN-F57QL28JQC8.maryem.info #550 5.7.1 Unable to relay ## Original message headers: Received: from exchangeserver01.mydomain.com ([10.0.10.30]) by exchangeserver01.mydomain.com ([10.0.10.30]) with mapi; Thu, 9 Dec 2010 10:44:42 -0500 From: Matt Laugh <MLaugh@mydomain.com> To: Ashgan Osman <ashgan.osman@clientsexternaldomain.org> CC: Paul Kissing <PKissing@mydomain.com>, Jennifer Happy <JHappy@mydomain.com>, "dlouie@sb-architects.com" <dlouie@sb-architects.com>, "aziz@clientsexternaldomain.org" <aziz@clientsexternaldomain.org>, 'Sherif El-Abd' <sherif.elabd@clientsexternaldomain.org> Date: Thu, 9 Dec 2010 10:44:41 -0500 Subject: RE: Egypt Housing Schedule Thread-Topic: Egypt Housing Schedule Thread-Index: AcuRkV2dZTvIVLBxQBq652mlkQiMxQEh4iEAADNYJNAANFhkMA== Message-ID: <9D3441FE2F85B044A5A4AAC3BF6D024D13F2D572DE@exchangeserver01.mydomain.com> References: <9D3441FE2F85B044A5A4AAC3BF6D024D13F2D57095@exchangeserver01.mydomain.com> <001801cb96ea$0225b390$06711ab0$@osman@clientsexternaldomain.org> In-Reply-To: <001801cb96ea$0225b390$06711ab0$@osman@clientsexternaldomain.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: yes X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/related; boundary="_005_9D3441FE2F85B044A5A4AAC3BF6D024D13F2D572DEexchangeserver01mydomain_"; type="multipart/alternative" MIME-Version: 1.0

What you have found is that their (not there) mail server does not accept mail for the address you entered.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

On Thu, 9 Dec 2010 17:41:04 +0000, xchangepatewon wrote: >i had a user contact me saying he cant send email to some of his clients today. i tried telnetting to there mail server and i can get connected, but when i type in the clients email address and hit enter i get. see output below: > >220 WIN-F57QL28JQC8.maryem.info Microsoft ESMTP MAIL Service ready at Thu, 9 Dec 2010 19:26:04 -0800 helo mydomain.com 250 WIN-F57QL28JQC8.maryem.info Hello [my external email ip address] mail from:administrator@mydomain.com 250 2.1.0 Sender OK rcpt to:client@theexternaldomain.org 550 5.7.1 Unable to relay > >the way i am understanding the telnet output is that the problem is on the external domain side? Yes. >can anyone assist me with this? if it is a problem on my end what is the best way to start troubleshooting this? > >here is the NDR my user received: > >Diagnostic information for administrators: Generating server: exchangeserver01.mydomain.com ashgan.osman@clientsexternaldomain.org WIN-F57QL28JQC8.maryem.info #550 5.7.1 Unable to relay ## aziz@clientsexternaldomain.org WIN-F57QL28JQC8.maryem.info #550 5.7.1 Unable to relay ## sherif.elabd@clientsexternaldomain.org WIN-F57QL28JQC8.maryem.info #550 5.7.1 Unable to relay ## Original message headers: Either they've fixed whater their problem was, or they have you in a block list. I tried connecting to the server and it likes me! 220 WIN-F57QL28JQC8.maryem.info Microsoft ESMTP MAIL Service ready at Fri, 10 Dec 2010 05:10:01 -0800 helo XXXXX.com 250 WIN-F57QL28JQC8.maryem.info Hello [XX.YY.ZZ.18] mail from:<me@XXXXX.com> 250 2.1.0 Sender OK rcpt to:<postmaster@maryem.info> 250 2.1.5 Recipient OK rcpt to:<xxx@maryem.info> 250 2.1.5 Recipient OK --- Rich Matheisen MCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP

looks like they removed the problematic server/mx record which was causing the issue. i am now able to telnet in successfully without the previous errors. thanks for your assistance Rich and Ed.