451 4.7.0 Temporary Server Error

451 4.7.0 KB ID 0001823


If you attempt to connect to and send mail via command line to your Exchange Server, you may see the following error after you end the data section of the operation.

451 4.7.0 Temporary server error. Please try again later. PRX5

Solution 451 4.7.1 Error

Log into Exchange Amin Center > Mail Flow > Receive Connectors > Default Frontend {Server-Name} > Edit > Scope > Select the IPV4 entry (Either Remove it and ad a new one or edit it)

451 4.7.0 temporary server error

Specify the IP address you want to use.

451 4.7.0 temporary server error

So, it should look like this > Save > Exit Exchange Management.

451 4.7.0 temporary server error

Open Notepad (Note: you need to run as administrator). Navigate to C:\Windows 32\Drivers\Etc locate the hosts file (If you can’t see it change the option to “All Files

451 4.7.0 Hosts File

At the bottom of the file enter the IP hostname and FQDN of the server then save and exit.

451 4.7.0 Hosts File

Then restart the Exchange Transport Service.

451 4.7.0 Restart Transport Service

Related Articles, References, Credits, or External Links

Exchange 2013 / 2016 / 2019 Default Receive Connector Settings

Author: PeteLong

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  1. For me, the problem ultimately was on the DNS server on the DomainController
    The A record for the Exchange server still referred to the old IP address after it was migrated, after i change it to the new Ip adres and reboted the exchange server it works

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  2. Thnak you – you saved my loife with this fix – hours of triubleshooting and the fix is so simple

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