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Exchg 2K - #5.5.0 smtp;550 Blocked

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  • Exchg 2K - #5.5.0 smtp;550 Blocked

    I'm sorry if I double-posted, I think I looked everywhere...I'm having an end user get the following error:

    The following recipient(s) could not be reached:

    [email protected]' on 2/21/2008 12:00 PM
    There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
    <hostname.domain #5.5.0 smtp;550 Blocked>

    Anyone have an idea on a fix? Yes, I do have current, valid MX/PTR records.

    Thank you for your assistance.

  • #2
    Re: Exchg 2K - #5.5.0 smtp;550 Blocked

    The remote site is blocking you. You need to find out why.
    You can use some of the tools to see whether your DNS is configured correctly - is one such site. If the server isn't announcing itself correctly then that can cause a block. Otherwise the recipient needs to look in their logs and tell you why the message is being blocked.

    Simon Butler
    Exchange MVP

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    • #3
      Re: Exchg 2K - #5.5.0 smtp;550 Blocked

      Thank you, Simon. My DNS records are indeed correct. I've ran numerous DNS Reports (don't use DNS Stuff/Reports any longer because it's not free) I assumed that the remote site is blocking us for some reason. It actually doesn't surprise me as I work for a financial institution that has to deal with spam/phishing attempts constantly. That may be why they're blocking us. I'll check it out...thank you for your assistance!