I thought I would follow up with the solution to this. We had not set up an external MX record to point to our internal mail server, although it had a NATed external address.
The error was caused by the remote servers trying to do a DNS resolution to verify that we were a valid mail server. That, of course failed thus resulting in the 5.1.8 error. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Tuesday, August 31, 2004 3:58 PM To: Exchange Discussions Cc: Exchange Discussions Subject: Problems sending Exchange 2003 mail to the Internet We have our Exchange server connected directly to the internet. I have specified that the SMTP Virtual Server resolve DNS names through external servers. But It will not send mail out. We get the following error: The e-mail address could not be found. Perhaps the recipient moved to a different e-mail organization, or there was a mistake in the address. Check the address and try again. <mail.dsst.hs #5.1.8 smtp;553 5.1.8 <[EMAIL PROTECTED]>... Domain of sender address [EMAIL PROTECTED] does not exist> It neither sees the external domain AND gives an error about the internal domain. Mail to users internally works fine. Any suggestions? Thanks, Michele Cooper _________________________________________________________________ List posting FAQ: http://www.swinc.com/resource/exch_faq.htm Web Interface: http://intm-dl.sparklist.com/cgi-bin/lyris.pl?enter=exchange&text_mode=&lang =english To unsubscribe send a blank email to %%email.unsub%% 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. _________________________________________________________________ List posting FAQ: http://www.swinc.com/resource/exch_faq.htm Web Interface: http://intm-dl.sparklist.com/cgi-bin/lyris.pl?enter=exchange&text_mode=&lang=english 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.
