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Jozi Zurbej's avatar
Jozi Zurbej
Copper Contributor
Feb 22, 2021

Problem with mail delivering via SSL error 454 4.7.4

Hi we have problem with delivering mail from fortimail appliance to exchange 2016 infrastructure, sometimes emails stuck at fortimail and not delivered to exchange with this message: 

 

dsn=4.0.0, stat=Deferred: 454 4.7.4 temporarily failed to deliver message via SSL/TLS.(Reason:454 4.7.4 temporarily failed to deliver message via SSL/TLS.)

this errors ocasionally occurs and emails are going to timeout and not delivered after few days,

I cannot find nothing about this error code, and to troubleshoot.

 

Thank you

2016
Exchange Server

1 Reply

  • MDadarkar's avatar
    MDadarkar
    Brass Contributor
    Feb 23, 2021

    Jozi Zurbej 

     

    Hi,

     

    The issue can be caused by one of the following reasons:

    • The Exchange server is experiencing Time synchronization issues.
    • There is a replication issue between the domain controllers.
    • The Exchange server is experiencing Service Principal Name (SPN) issues.
    • The required TCP/UDP ports for the Kerberos protocol are blocked by the firewall.

    https://docs.microsoft.com/en-us/exchange/troubleshoot/client-connectivity/454-4-7-0-temporary-authentication-failure 

    https://www.thecloudtechnologist.com/how-to-fix-exchange-online-hybrid-outbound-connector-454-4-7-5-certificate-validation-failure/ 

    Regards,

    MD

     

     

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