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Fix Exchange Error 450 4.7.1 – Step by Step Guide

Ugra Narayan Pandey | Modified: 2021-11-17T12:40:16+00:00| Error | 4 Minutes Reading

While using Exchange 2010 or 2007 user encounters Exchange error 450 4.7.1. In this error whenever they sent an email, the remote Exchange server will disapprove the email and the user will get this error while sending an email from some specific domains.

Exchange error 450 4.7.1

The one scenario when user will face this issue, when IP address from where mail is sent does not have PTR record, therefore, the Exchange Server will rejects that email. PTR Record is also known as pointer records, PTR record is generally used for mapping a network interface IP to a host name in reverse DNS. There are also other reasons that causes this Exchange error 450 4.7.1 are mentioned in the below segment.
In order to tackle this problem, user can contact their ISP (Internet Service Provider) to add an PTR record in their Server IP or also can check two things first is receive connector that creates problem in HELO/EHLO while verifying the server identity. Also by making sure that user have added correct FQDN of the Server.

Factors Responsible For Getting Exchange Error 450 4.7.1

  • When admin sets the limitation on total number mail that can be send by the user, in that case when user exceeds their limit then user will get the error.
  • ‘450 4.7.1 Recipient address rejected: Policy Rejection- Quota Exceeded’

  • User also can get this error while sending an email from specific domains, the server will rejects the email that has been sent from one of these domain.
  • ‘450 4.7.1 Client host rejected: cannot find your reverse hostname’

  • When Exchange server not able to find out the sender of mail or not able to find out the hostname, in that case Exchange error 450 4.7.1 is generated that will display that server can not find out reverse hostname. In this server performs reverse look up, in order to find out the address from where email is sent.
  • Note: Reverse DNS lookup find Domain Name associated with IP address using DNS of internet.

  • Some email addresses are blocked by Exchange Server, when user will send email to these blocked users, they will get this error code.
  • While sending an email to invalid users the sender will encounter the following error:
  • ‘450 4.7.1 Recipient address rejected: Access denied.’

  • This error message also occurs if IP address from where email is sent does not have PTR record, PTR Record is also known as pointer records. There is need of PTR record for mapping IP to a host name in reverse DNS.

Resolution Of Exchange error 450 4.7.1

  • When any IP address sends any spam links or data, then generally that IP address is blocked by the server. In order to resolve this issue, there is need of removing IP address from the server’s blacklist.
  • One can contact internet service provider in order to PTR record in their IP address.
  • Domain records of DNS must be properly setup and by checking the mail server configuration.
  • Must setup reverse DNS with Fully Qualified Domain Name (FQDN).User can contact ISP for creating FQDN that should always be end up with valid domain name.
An Alternative Way to Fix the Problem

Apart from the manual method, there is an alternative way, Exchange Server Recovery Tool, which can fix any type of including Exchange error 450 4.7.1. Most of the errors are caused by corrupt Exchange database. And when it comes to repair the highly corrupted database, the tool turned out be the best way to resolve all the issues related to Exchange Server.

Conclusion: This Exchange error occurs in different scenarios as discussed above, Due to occurrence of the error, sender can not send an email as the mail will be rejected from Exchange server site. This problem can be easily tackled by following mentioned resolutions.