I have sent several test emails to various users as part of distribution lists I created in exchange. I have also received several different types of error messages in response. Can I get some help interpreting and fixing the following problems? TIA! #1) There was an SMTP communication problem with the recipient's email server. <exchange.abc.local #5.5.0 smtp; 550 #5.1.0 Address rejected> #2) There was an SMTP communication problem with the reipient's email server. <exchange.abc.local #5.5.0 smtp: 550 MAILBOX NOT FOUND> #3) There was an SMTP communication problem with the recipient's email server. <exchange.abc.local #5.5.0 smtp; 550 Requested action not taken: mailbox unavailable> #4) The destination server for this recipient could not be found in Domain Name Service (DNS). Please verify and retry. <exchange.abc.local #5.4.0> #5) The message cannot be delivered due to a configuration error on the server. <exchange.abc.local #5.3.0 smtp; 553 5.3.0 Addressee unknown, relay=[24.123.106.46]> Thank you again for any help!

Hi, You'll need to be more specific about your environment. Include information on all mail servers. Describe your test scenarios that are failing, for example is it all internal mail on the same server, or is it internal mail on different server, external mail or some mix of all of the above. -matt

I'll do my best, but I'm new at this, so if I don't get it right the first time, bear with me. These errors are all the result of external contacts created. In AD I created a new contact with an SMTP email address pointing to an external email address given to me by the contact. Then I created a distribution list using the contacts. When I try mailing using Outlook from my exchange server to the email address, I get the variety of error messages. I haven't done any testing beyond receiving the error messages and making sure I entered the external email address correctly. Does that make any sense or am I just as clear as mud? Sorry

Oh, and if I need to provide more detail and/or info, let me know.

Please clarify a few things... Is this a new environment? Or is/has this environment been in production fora while? Do you have external email flow? If you send an email to your hotmail (or other) account do you get it? Do you have internal mail flow? If you send an email from your hotmail (or other) account intoyour environmentdo you get it? -matt

Hi, Whetherthe Distribution list include only contact user? Did you try to send the email to the separate contact one by one? Whether this issue still occurs when sending the email to each contact? Thanks Allen