Exchange Error 550 Introduction & solution

MS Exchange Server is the most preferred emailing server that facilitates online as well as offline email access. To access online, one can use OWA that stands for Outlook Web Access and to work in offline or cached exchange mode, MS Outlook can be used. 

On Exchange Server, users’ mailbox data including emails, calendar, contacts, and other valuable data including all public folders are stored in EDB files. Well, a single exchange database may have a number of EDB files, which is actually dependent on the number of users in a common domain. 

However, the administrator must be aware of the fact that the EDB files are delicate and may lead to corruption anytime due to virus attacks, dirty computer shutdown, or any other technical issue. 

In order to ensure integrity of the EDB files and for online database maintenance regularly, Exchange Server performs not only checksum, but online defragmentation as well. The longer the EDB file is maintained successfully, the healthier is the Exchange database. However, since you are the administrator, you must understand how significant it is for the EDB files to store mailbox data of all your clients. In fact, even a minor issue in an EDB file may cause loss of crucial data of the users and hence, that of the organization. 

Mentioned below is an error that prompts when Exchange Server fails to deliver an email to the address of the receiver, as it is outside the organization’s domain:

Error: “Exchange Serer error 550 5.7.1 Unable to relay”

Being more precise, when an email address on a particular domain is used to send email messages outside the domain (however, it is not privileged to do so), exchange error 550 is encountered. Well, the term domain refers to the group of users sharing information with each other on a particular network that is based on some predefined protocols. An Exchange administrator is the only one who has the privilege to control information exchange via emails across  the group as well as outside the domain. 

In technical terms, the statement, “since the outgoing mail server (i.e. SMTP) fails to authenticate the email address of the sender, it is not privileged to send emails outside the domain.” signifies the error in a precise way. 

In divergence, considering the error from receiver’s viewpoint enlightens another facet of the scenario, which states that it also could be like that the receiver is not privileged to receive email messages from email addresses outside his or her domain. If not, then Exchange Server or its database most likely is severely corrupt and potentially generating error.

In order to fix the error, the administrator must look for some Exchange Server inbuilt utilities. Well, he can consider following the process discussed underneath:       

•  At the very first step, launch Exchange Server Manager and proceed with the following path: Administrative Group > Administrative Group Name > Server > Server Name > Protocols > SMTP.
• Then after, right click the Default SMTP Virtual Server and select Properties.
•  Go to the Access tab, click Relay and select “Only the list below” to add your domain/IP in the list and relay it.

·   However, the check box “Allow all computers which successfully authenticate to relay, regardless of the list above” must be checked. 

Note - In case Exchange error 550 is encountered again, you must consider using an Exchanger recovery tool.  Leading tools available in the market are – 

·         Stellar Phoenix Mailbox Exchange Recovery

·         Granular recovery for Microsoft Exchange

·         Enstella Exchange Recovery Software

Before purchasing any of the above tools, it would be a good practice to check the reviews of software. One such software review is live here - http://exchangeonline.in/product-review-stellar-phoenix-mailbox-exchange-recovery-v5-0/