20 comments on “451 4.7.0 Temporary server error. Please try again later. PRX2

  1. Thanks – spot on on my problem! I had network adapter configured with one internal DNS and one external. Remove external DNS server and ipconfig /flushdns and emails was flying in and out.
    I guess Exchange 2013 is a little more sensitive to DNS as opposed to Exchange 2010. The external domainname for emails exists in internal DNS so strange that the exchange 2013 will goΒ΄to external DNS to lookup names…
    Thanks again πŸ™‚

    BR Soren

  2. Finally a solution that solve my very same issue. Spend hours trying to undo/redo the settings in EAC without much help. Glad I came across this fix

  3. Thanks i was stumped on this one for a while I was sending internal external and receiving internal but not receiving external emails i tried this link to troubleshoot https://testconnectivity.microsoft.com which i then found the error which led me to this page. You wouldn’t think something so simple that works on older servers would be the issue. Great find!!

  4. Holy crap!! .. days … more configuration changes than Carter has little liver pills. The pile of hair I’ve pulled out has reached my seat.

    Thank you.

  5. Like a charm! Lab is now up and sending mail both ways successfully! Thanks for that tidbit. After changing both the Internal DNS Lookups and External DNS Lookups to use the specified DNS server, I would have figured that I was good to go, but nope. I had to actually remove the DNS Server entries from the NIC that I didn’t want to use. Crazy. Given that I spend most of my time on Lync and Skype for Business servers, this posting really prevented me from chasing my tail in circles with Exchange. Thanks so much!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s