550 5.7.1 Unable to Relay Exchange Server 2010 / 2013 Error – Solved
While working on Microsoft Exchange Server, one of MS Outlook user encountered an Exchange Server error 550 5.7.1 unable to relay [See Full Details Below] issues in their account. In this post, we will see the details including possible cause, related error, technical background on 550 5.7.1 unable to relay Exchange Server 2010 error and find out the best possible solution.
Error code: smtpaddressfailedexception 550 5.7.1 unable to relay Exchange 2010 / 2013 Server for email@example.com
Related Error code: 5.0.0, 5.7.1, 5.7.3,
Possible Cause – Exchange 2010 Error 550 5.7.1 Unable to Relay
- User failed to authenticate on the mail server.
- The receiver domain’s recipient policy has imposed restrictions on the sender’s domain / department.
- The Exchange Database is corrupt.
- In case you try to send email on large number of domains.
- Outgoing Mail Server is not able to recognize sender.
- Non Existence of Policy for expected domain in the organization.
Technical Background behind the error 550 5.7.1 unable to relay Exchange
To understand the technicality behind SMTP server response 550 5.7 1 unable to relay Exchange 2010. We need to understand what is mail relay first?
A mail relay is also referred to as email server which is responsible to route an email to its correct destination. A server that has ‘Relaying turned on’ will accept mail for recipients in other domains, then attempt to redeliver it. A very similar practice is applied on Exchange Server; to allow SMTP service. There are two kinds of SMTP relay configurations:
- Internal SMTP relay: Send Email to recipient within organization.
- External SMTP relay: Send Email outside the organization.
This Mail Relay generally happens when you connect to a mail server on one domain and trying to send emails using another server on an external domain. This 550 5.7.1 unable to relay Exchange 2010 / 2013 error signals that the outgoing mail server is unable to recognize you and hence, won’t allow you to send emails. Another possible reason may be that there is no recipient policy for the expected domain in your organization.
By default, Exchange Server 2003, 2007 and 2010 are not configured to accept incoming email from the internet. But if you are running Exchange 2013, it is by default configured with a Receive Connector called “Default Frontend” which allows “Anonymous Users” to connect.
How to Fix 550 5.7.1 unable to relay Exchange 2013 Error ?
In order to resolve the issue SMTP Server response 550 5.7.1 unable to relay Exchange 2010 error codes; you can follow the below mentioned possible solution:
Manual Method – Solve Exchange Server Error 550 5.7.1 Unable to Relay
You can remove the 550 5.7.1 relaying denied error manually by using Exchange Management Console (EMC) for Exchange Server 2003/2007 and 2010 or Exchange Admin Center (EAC) in case of Exchange Server 2013.
Allow all computers to successfully authenticate to relay. How to do that see below-mentioned steps:
- Step 1: Start Exchange Server Manager and go to the Administrative Groups.
- Step 2: Select Administrative Group Name -> Server -> Server Name -> Protocols -> SMTP.
- Step 3: Right click on Default SMTP Virtual Server and open Properties.
- Step 4: Go to Access tab > Relay > Only the list below.
- Step 5: Select the checkbox ‘Allow all computers which successfully authenticate to relay, regardless of the list above‘.
Bringing It All Together
The write-up provides detailed information to resolve the error: 550 5.7.1 unable to relay Exchange Server 2010. This error can be occurred also due to the corruption of EDB database. So, you can use eseutil repair tool (which is built in tool in Exchange Server for repairing) or you can try Exchange Mailbox Recovery software in case you are looking for simple and fast repairing solution of your corrupted EDB.