A commonly noted error in Microsoft Exchange 2007 server is when the emails from certain 3rd party applications or scripts fail to deliver.
The mails get rejected, giving this error message in the logs:
SMTP MAIL command failed Error (501) 5.1.7 Invalid address
Today, we’ll see what this error means and how to fix it in Exchange server.
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What is error ‘501 5.1.7 invalid address’?
As we all know, a valid email address has the format – user@domain.com. But in many email applications, people give the alias names in mail address fields – say, just ‘username’.
In older versions of Exchange, the default domain name gets appended automatically to these alias entries given in ‘MAIL FROM:’ or ‘RCPT TO:’ fields of email applications.
So, even if aliases are used, they get automatically converted to fully qualified email addresses by the Exchange server. But from Exchange 2007 onwards, this feature is absent.
So, when mail users try to send a mail with just an alias name, Exchange 2007 DOES NOT replace it with the full mail address, and it results in ‘501 5.1.7 invalid address’ error.
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How to fix email error ‘501 5.1.7 invalid address’
To resolve the mail delivery error ‘501 5.1.7 invalid address’, the solution is to ensure that all the email addresses in the applications are in the proper format.
Since its not practically feasible to edit all existing applications and update the ‘MAIL FROM’ and ‘RCPT TO’ fields manually, an easier way is to set a default domain name for Exchange.
So, if you’re using Microsoft Exchange mail server 2007 or above and it is rejecting emails with the error ‘501 5.1.7 invalid address’, here is the fix:
The ‘DefaultDomain’ parameter specifies the domain name to append to aliases given in the ‘MAIL FROM’ or ‘RCPT TO’ fields for emails sent from applications.
The steps to set the default domain value on the receive connector are:
1. Access Microsoft Exchange Server 2007 and click on the Exchange Management Shell.
2. Verify the current setting of the default domain value on the receive connector using this command:
Get-ReceiveConnector -identity <ReceiveConnectorName>|fl
The value of DefaultDomain that is shown in the output would be blank by default.
3. Set the default domain value to the main domain name you want to append to the email aliases, using the command:
Set-ReceiveConnector -identity “<ReceiveConnectorName>” -DefaultDomain “<DomainName>”
Now this domain name would be appended to the email addresses in the applications that sent mail to or relay mails via this mail server, causing them to deliver fine.
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In short..
For email applications, its always good practice to use fully qualified email addresses for sender and recipient fields. This would help avoid email spoofing and mail bounces.
Too many instances of error message ‘501 5.1.7 invalid address’ in the mail logs can also denote spamming in the server via some malicious scripts.
Securing the mail server and the email applications is very crucial to avoid spamming and blacklisting of the servers, and to ensure successful mail delivery.
If you’d like to know how to secure your mail server and prevent email bounce errors, we’d be happy to talk to you.
[ Are your users complaining about email errors? Get our server specialists’ assistance to fix your mail server. ]
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thanks for the information provided by you it’s really a great help from your side
Thanks for sharing this information, Well explained Solution for this error.
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