Problem sending mail from Exchange 2007 SMTP RRS feed

  • Question

  • When trying to send mail using Exchange 2007 SMTP connectors with a POP3 configuration within Outlook Express, we get the following message.


    The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was 'jdoe@nospam.com'. Subject 'test', Account: 'mail.somedomain.com', Server: 'mail.somedomain.com', Protocol: SMTP, Server Response: '550 5.7.1 Unable to relay', Port: 25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC79


    That message is received even from within the local area network, but also received outside the network.


    A check of the application event log shows this event right after a send attempt.


    Microsoft Exchange couldn't find a certificate that contains the domain name mail.somedomain.com in the personal store on the local computer. Therefore, it is unable to offer the STARTTLS SMTP verb for any connector with a FQDN parameter of mail.somedomain.com. Verify the connector configuration and the installed certificates to make sure that there is a certificate with a domain name for every connector FQDN.


    While the server is using SSL (port 995 for POP3), it is using port 25 (unsecured) for SMTP. 


    I realize there is probably some sort of authentication issue, but I have never had this problem with previous versions of Exchange. If you authenticate to the SMTP server with your domain login, which OE's configuration is set to do, it has always worked in the past.


    Anyone have any ideas?



    Wednesday, July 18, 2007 5:36 PM

All replies

  • Exchange 2007 by default requires TLS encryption before it allows BasicAuth. Your logs tells you that there is no certificate with the name the receiveconnector advertise itself with and therefore it will not allow TLS encryption and BasicAuth.

    You can try to use another auth mechanism like NTLM or allow BasicAuth without TLS. its done on the receiveconnector and authentication tab.


    Wednesday, July 18, 2007 6:34 PM