How To Deal With Exchange Server Error 450

Exchange server is a mail server that runs on Windows Server was introduced by Microsoft. The application is enhanced with a bundle of features that facilitate the users to work easily with it. But as they say nothing is perfect. Same is the case with Exchange server. Although working with Exchange server results in a flawless database, sometimes few errors can also be encountered. In this blog we will discuss one of the errors of Exchange server i.e. Exchange Server Error 450.



Different Scenarios Resulting In Error 450

I. The major and the foremost reason when the Exchange users can experience this error is when the email sent by the user is rejected by the mail server. This issue is only observed with some domains whereas no such error is observed with other domains.

The error basically implies that the server is doing reverse look ups so as to determine the address from which you are sending the mail. Suppose when you send mails from user@domainname the system gets marked with the IP Address. When the email reaches the server from user@domainname, the server checks the whether it is coming from the same domain by checking if the IP address is pointing to user@domainname.If the server fails to detect that the mail is being sent from the same sender or does not identify the hostname, the error is generated.

II. This error is encountered by the user when the user is currently receiving a large number of mails and the error is generated by the incoming mail server.

III. The Exchange Server Error 450 is also encountered at an instance when the recipient address is not valid and the access to the server is denied. Also one of the reasons can be that the server has blocked the recipient address.

Workaround To Exchange Server Error 450

If you are encountering the above error due to the first scenario, then the issue can be solved by getting a check done on the Mail Server Configuration and also check whether the domain records of the DNS are setup properly.

Reverse DNS Check

Check your domain and find if your Reverse DNS is setup with a Fully Qualified Domain Name (FQDN) and not to an Internet Service Provider generic.In case you do not possess one setup then contact the Internet Service Provider and ask them to create or setup one connection to the FQDN. The FQDN should not end up with anything that is invalid domain name. If this is the case, then change the name otherwise the problem of sending mails to some server will persist.

Blacklist Check

In case your IP address is marked in the blacklisted IP Addresses, then this is the reason that you are encountering problems while sending your mails to some domains. Check out the reason why your IP is blacklisted. It may happen that your system is sending spam and you are unaware of it. Fix this issue and request for removing your IP from blacklist.

Conclusion
To avoid the occurrence of Exchange error 450, keep in mind to keep a check on your domain settings. Also a timely check of your IP address can ensure that you will not encounter this error.