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Exchange 2013 Email Flow Failed- 451 5.7.3 Cannot achieve Exchange Server authentication RRS feed

  • Question

  • Hi All, 
    Good Day!!!,

    We are setup new exchange 2013 in our existing Exchange 2007/2013 (Site1)environment
    After setup new Exchange server into Site 2, email flow to internal mailbox is working, But External domain is failed.

    local domain to local domain - mail flow is working fine
    Local domain to External Domain - mail flow failed

    The error message at email queue

    Remote Server at MBX01.Domain.com (192.168.0.15) returned '451 4.4.0 Primary target IP address responded with: 
    "451 5.7.3 Cannot achieve Exchange Server authentication." Attempted failover to alternate host, but that did not succeed. 
    Either there are no alternate hosts, or delivery failed to all alternate hosts. The last endpoint attempted was 192.168.0.15:25'

    thanks in advance

    Regards, Kesavan K M. Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Thursday, February 2, 2017 12:20 PM

Answers

  • Hi Allen,

    Thanks for your reply. It Was helpful .

    Actually when when we check the telnet from site 1 to site 2 and wise versa we could not get the telnet response from any of the exchange servers.

    So we found a solution to disabled smtp port scanning at CISCO PIX Firewall.

    no fixup protocol smtp 25

    After run above command by network team we could able to communicate both side.

    thanks,


    Regards, Kesavan K M. Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    • Marked as answer by kesa_kara Tuesday, February 7, 2017 7:34 AM
    Monday, February 6, 2017 11:13 AM

All replies

  • Hello,

    Do you add this new installed server into source Transport Servers list in Internet send connector?

    If not, you can login EAC and switch to mail flow -> send connectors -> double click the Send Connector -> scoping -> click "+" underneath Source server, then add new Exchange 2013 server.

    Besides, if you have some special receive connector (may be relay connector), please remove the new Exchange server's IP from the remote IP ranges on those connectors. Otherwise, the mail flow to outbound from this new server will fails.

    Best Regards,

    Allen Wang


    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    • Proposed as answer by Akabe Friday, February 3, 2017 7:13 AM
    Friday, February 3, 2017 6:55 AM
  • Hello,

    Any updates about this issue?

    Please feel free to let me know if you need further help.

    Best Regards,

    Allen Wang


    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Monday, February 6, 2017 1:59 AM
  • Hi Allen,

    Thanks for your reply. It Was helpful .

    Actually when when we check the telnet from site 1 to site 2 and wise versa we could not get the telnet response from any of the exchange servers.

    So we found a solution to disabled smtp port scanning at CISCO PIX Firewall.

    no fixup protocol smtp 25

    After run above command by network team we could able to communicate both side.

    thanks,


    Regards, Kesavan K M. Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    • Marked as answer by kesa_kara Tuesday, February 7, 2017 7:34 AM
    Monday, February 6, 2017 11:13 AM
  • Thus, is it solved by disable SMTP port scanning at CISCO PIX Firewall?

    If so, please mark your reply as answers to highlight it. Also, mark the helpful response as the answer and/or vote them helpful as appropriate.

    Best Regards,

    Allen Wang


    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Monday, February 6, 2017 3:08 PM