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Computer101<br />
EE Admin
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Hello, we have a customer that is unable to send us email, but they state they have not had trouble with other companies. &nbsp;Our mail goes through a spam filtering service first and their tech support indicates:<br />
&quot;The error they are seeing is because their server is responding too slowly to the smtp commands. Our servers timeout after 60 seconds of no response.<br />
This is not something that is adjustable&quot;<br />
I performed the following test at dnsstuff.com and received:<br />
Could not connect: Got an unknown RCPT TO response: 451-74.53.59.133 is not yet authorized to deliver mail from 451. &nbsp;Please try later.<br />
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This appears to be an authentication problem, but can anyone shed more light on the subject so we can inform our customer accordingly?<br />
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Hello, we have a customer that is unable to send us email, but they state they have not had trouble with other companies.  Our mail goes through a spam filtering service first and their tech support indicates:
"The error they are seeing is because their server is responding too slowly to the smtp commands. Our servers timeout after 60 seconds of no response.
This is not something that is adjustable"
I performed the following test at dnsstuff.com and received:
Could not connect: Got an unknown RCPT TO response: 451-74.53.59.133 is not yet authorized to deliver mail from 451.  Please try later.

This appears to be an authentication problem, but can anyone shed more light on the subject so we can inform our customer accordingly?



Mail delivery issue: unknown RCPT TO response: 451

Within Internet message handling services (MHS), a message transfer agent or mail transfer agent (MTA) or mail relay is software that transfers electronic mail messages from one computer to another using a client–server application architecture. A MTA implements both the client (sending) and server (receiving) portions of the Simple Mail Transfer Protocol (SMTP). The terms mail server, mail exchanger, and MX host may also refer to a computer performing the MTA function. The Domain Name System (DNS) associates a mail server to a domain with mail exchanger (MX) resource records containing the domain name of a host providing MTA services.