I'm getting the dreaded "

451 4.7.0 Temporary server error. Please try again later. PRX2

" error when receiving SMTP mail.

does anyone know exactly what causes this error? there are many references to it on the web, but nobody seems to know exactly what causes it. maybe it's something to do with DNS?

can someone please ask someone on the exchange team to help document this?

• Edited by spongman Saturday, January 12, 2013 7:40 PM

The Internet-facing NIC should be configured with DNS servers. The internal NIC should not.

if that's the case, how does the exchange server resolve internal domain addresses?

why does it matter which NIC is configured with which DNS server?

• Edited by spongman Sunday, January 13, 2013 7:44 PM

Hello,

Just had the same issue 2013 exchange.

The answer for me was to check the two boxes in the network configuration (See below) on the internal Network Card, This cured it immediately.

I wish I could explain why since the IP of this server is registered statically in DNS so this seemed superfluous.

• Proposed as answer by bpatterson_ci.ammon.id.us Thursday, October 31, 2013 1:02 AM
• Unproposed as answer by bpatterson_ci.ammon.id.us Thursday, October 31, 2013 1:03 AM
• Proposed as answer by bpatterson_ci.ammon.id.us Thursday, October 31, 2013 1:08 AM

Bill, have you solved this issue I had the same issue here:(, hope you can help me out.