Exchange Server 2007 SP3 UP11 Unable to send only 1 email. RRS feed

  • Question

  • Hi to all.

    We had try to send some emails to our customers.
    Most of them sent without problem, some of them return back and the reason is unknow recepient (logical)
    One email our exchange server try more than 2.000 times to send it without success
    before we take 550 4.4.7 Queue Expired.
    When the email is in queue we received Last Error 450 4.5.0 No recepient succeded.
    When i have try to send via telnet after the rcpt to:xxx@xxx.com
    show me 550 5.7.1 Unable to relay.

    Our Exchange server use a dedicated IP, we have a valid SPF Record and also reverse DNS records. Any Idea we we are not able to send the email?

    PS: The specific recepient is a valid email address.

    Thanks and regards.

    Friday, December 6, 2013 1:54 PM


  • Check your SMTP Send protocol log. Do you see those "450 4.5.0" status codes? Is the IP address of the target server the one you expect? It wouldn't be the first time I've seen an organization forget to remove a MX record for a server that's no longer supposed to be used for e-mail.

    You can also use sites like http://mxtoolbox.com to see if their tools have the same problem (or connect to the same server).

    If the other MTA is Postini's, this might help:


    --- Rich Matheisen MCSE&I, Exchange MVP

    Saturday, December 7, 2013 3:36 AM

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