Know About the Occurrence of Exchange Server Errors 550, 551, 552, 553, 554

The deployment of Exchange server environment in an organization certainly has a positive impact on the business process. However, when it comes to maintaining and managing Exchange server for resiliency in a company, system administrators come across a lot of challenges. Here you will become conversant with the best approaches and practices for trouble shooting errors that are normally observed in Microsoft Exchange Server.



Occurrence of the Errors

Often system administrators come across issues over Exchange Server when they receive an error stating that “Unable to relay” and they are unable to send email messages to a particular domain. The error codes 550,551,552,553,554 typically refer to undeliverable messages issues. The screenshot for the error is given below

In Exchange server 2003

In Exchange Server 2010

The error normally appears when a user tries to send a message to email addresses that are located outside the domain of the organization.

Source of the Errors

The error codes mentioned above is indicative of email relay issue with the Exchange server. However, a deep delve look into the causes of the errors can help system administrators to resolve the error resolutely. Let us first figure out the reasons for the error. The possible causes for the occurrence of error can be due to any one of the following reasons

• Inability of the outgoing mail server for identifying the sender
• Some problems that hold off the authentication process of sender by the Exchange server thereby restricting the sender to send messages
• The domain recipient policy concerned with the receiver has put away with restrictions on the sender’s domain
• Corruption issues in the EDB database of the Exchange server

While the possible reasons for the errors has been discussed above, the most common cause for the number of errors mentioned over here is due to restriction in the authentication for relaying messages through the server or trying to send email messages without the process of authorization via the SMTP server.

Steps Taken to Address Error Issues

In case of Exchange server 2003

• Start the Exchange System Manager
• Now follow the settings given below

• Right click on SMTP Server to select the settings as mentioned below

• This directs user to a new window named as “Relay Restrictions” 
• Now select the option “Only the list below”

• Add the domain name or IP address to authorize with the relay
• Next enable the checkbox against the option for allowing the systems that authenticate to relay apart from the IP address mentioned in the list

In Case of Exchange Server 2010

When sending messages through Exchange server 2010, there is a provision that restricts relaying for specific hosts or devices. System administrators need to allow relaying for these devices for successfully sending the email messages through the Exchange Server. The Hub Transport Server has the responsibility for regulating SMTP communication in an Exchange Server environment.

For authorizing a non-Exchange Server to relay a mail message, system administrators have the facility to design a new Receive Connector on the Hub Transport Server. Keep up with the steps given below to design a Receive Connector

• Open the EMC and move to Server Management
• Navigate to Hub Transport and open it to select New Receive Connector

• A new window will come into view on the screen; name the Connector as Relay

• Select the Next tab that will again direct to Local Network Settings
• No Requirement to put up with any changes on the Local Network Settings
• In Remote Network Settings, select the IP range & click the red cross- mark to delete it

• Select the Add button and specify the IP address of the server to authorize relaying via the Exchange server

• Choose OK to add the IP
• After that click on ‘Next’ tab to exit with the process

A new Receive Connector has been created but it still restricts the relaying of email messages through Server. Catch up with the settings given below to allow relaying through Server.

• Open Exchange Management Console
• Select the newly coined Receive Connector
• Choose properties, and it will direct to the relay properties
• Out of the four tabs, click on Permission Group

• Enable the checkbox aside the option ‘Exchange Server’
• Next move to the Authentication tab

• Enable the checkbox aside ‘Externally Secured’

After employing all the modifications pointed out above, the newly created Receive Connector will be able to relay messages through Exchange Server.

The relay settings for Exchange Server 2007 are similar to Exchange server 2010 and hence one can follow them to set the SMTP relay.

Conclusion

A thorough analysis of the errors discussed in this blog, it was inferred that all the error codes were somehow inter related with the SMTP relay authorization issues. The methods that are discussed on the basis of different versions of Exchange Server can be helpful to users to resolve errors while sending email messages.