451 4.7.0 Temporary server error. Please try again later. PRX2
- Mohammed Niyas
- Apr 24, 2021
- 1 min read
Another day of troubleshooting with a student from Learn Exchange from beginner to master. A straight configuration of Exchange Server 2019 has completed successfully, but testing email reception were not successful.
I asked my student to manually emulate email SMTP communication, which ended up with the title error of this blog.
It points to a DNS resolution error. So I asked to check the network card bound for the internal DNS lookup can resolve the exchange server's DNS name.
A Quick fix to this issue is to add DNS entry to the local Host file.
C:\Windows\System32\drivers\etc\hosts.
192.168.16.1 server
192.168.16.1 server.domain.com
Great tip, I must add that this error result from migrating from Exchange 2016 to Exchange 2019. After removing Exchange 2016 we realize that inbound email did not came through so after checking with telnet we got the error and found the solution in your site. Thank you🙂